Any more people had the CE light problem with the new Borla header?? Anybody that had the problem before come up with a good fix?? (other than putting tape over the CE light) Anyone ever hear anything from SPO or Trey Cobb?? I like what I hear about the headers, but I don't wanna taunt the CE light...

I hope this is figured out soon. I plan on getting the new headers. Don't want to be a CE light boat... http://www.i-club.com/ubb-files/frown.gif

Cheers,
Tom Richardson, Jr.

I don't recall who posted -- midwest maybe -- that his dealer told him it couldn't be fixed so he put a switch in to turn off ce light as the default code is apparently somewhat benign. However, it isn't green as the problem causes the ecu to call for fuel and my mileage is down 25-30% w ethanol gas. Therefore non compliant..in no small way.

Scott Orem (www.spomotorsports.com) is working on it....perhaps trying smaller borla system to see if it triggers a "ce".

[This message has been edited by Greborb (edited November 30, 2000).]

It is a temperature (of exhaust gases) issue (too cold I believe) so Scott's idea of insulating headers and pipes could be the answer or more back pressure and higher exhaust temp (with smaller diam. cat-back system) could be a solution. He's on it and I believe he'll step up to the plate and orchestrate a solution.

Go Scott. http://www.i-club.com/ubb-files/smile.gif

[This message has been edited by Greborb (edited November 30, 2000).]

Welcome to this elite and growing group. Trey was inclined to believe it was the front O2 sensor, Carr Subaru concurred, and then said no....lets see how it works with the sti setup they had just installed....we think it might be a bum cat...based on the default code, which they had seen in older models with 80k mi..but no 000 or 01's. If it comes back on it could be the cat, O2's, or the borlas. Scott, at SPO Motorsports, is aware and analyzing...as well as working with SOA, Borla, and Carr Subaru. Scott believes there is the possibility the borlas and ecu might like a 2" pipe better such as the borla pipe and muffler.

Anyway I believe we've got the first team on it. If you want to test Trey's notion go and replace the front O2 sensor and report back to the R&D Committee. If the "team" is divided at all when mine comes on, I'll try the front O2 based on my great respect for Trey's opinion.

This is an unsolved gremlin....come hither "specialists" http://www.i-club.com/ubb-files/wink.gif

[This message has been edited by Greborb (edited November 30, 2000).]

Mines be turning on and off.

Js

Are any of you guys that are expierencing CE lights running any sort of engine / air fuel management? Thanks
Aaron

Ya, I know a guy running the headers with a S-AFC and he has a CE light... http://www.i-club.com/ubb-files/frown.gif

He said nothing shows up suspicious on the AFC.

Thanks, I was wondering if that would matter. Anyways, Another? Anyone running a egt? Just have to ask - somebody needs to be my guinnie (sp) pig.
Aaron

I have on order both an A/F and a EGT on order at Rallispec. And Yes I have an AFC.

Right now, the CE light comes and goes..
Maybe be temperature I dont know. I'm getting around 280 to 3/4's of a tank.

Hmmmmm

hmnn...lower mpg...too rich....front O2?

I have been running my headers for 4 months know without any CE light coming on.(knock on wood) I really could not begin to tell you guys what your problem is. I started with it on and stock exhaust, know I have the headers and a full S.S. dual tip Stromung exhaust. I have a my00 and I do run my car hard at times so it isn't because I'm babying it. The only other thing I did was reset the ecu after addind each part. I always love the way it opens-up with that roar.

I don't have a safc but John does. If Wraithmk3 isn't having problems I lean toward Trey's (and they've put borlas on a bunch of cars without any such problems)belief that it's the front O2 sensor.

Unless my 02 sensor has been bad since I got the car, thats been my average mileage.

I spoke to Nativo, who has the older style and he says he has the CE light alos but it goes on and off depending upon his fule level.

Anything from SPO or Trey

Aspen posted this regaurding a seperate issue... But it may help keep the temps up.
--------------------------------------------------------------------------------
I think people should get some thermotec heat wrap and wrap the up pipes just because everything is so close in that general area.
You can't go wrong with $25 and it does a very effective job and insulating heat. I had some on my headers and actually could touch the headers with my hands after a hard run. I plan on doing this to my turbo up-pipe when I get it done.


------------------------------------------

I spoke with Braden at www.SubySports.com (http://www.SubySports.com) and he sells Borla systems and confirms that they should be wrapped to keep the temps up or the CE will be more frequent.

Larry www.ImprezaRS.com (http://www.ImprezaRS.com)

Everythings related. Scott Orem, SPO MtrSpts,said he thought wrapping the header and pipe could be a remedy to raise exhaust temp. It's a distinct possibility as my experience today raises questions about the O2 as the culprit. Made a quick run to Seattle for Bike Show in 4-Wheeled motorbike. En route it was piloted by M3 friend who said the car felt more responsive and tracked better than his '99 M3 (his tires/steerg sys. diligently follow the ruts). I've driven his M3 and didn't disagree.

Temp was betw 50 and 60F. For almost 400 miles, we averaged 28.1 driving smooooth from 65-95 avg'g maybe betw. 75-80. Speedometer is spot on with time checks with rubber that's 3+% shorter in circumference!
No "ce" light and no rich running. Like normal. So outside temp was warm and it ran normally.

Scott also theorizes that borla system (header/cat-back are engineered to be together) and a 2" system. He thinks 2.25" is too big with less backpressure, lower temp etc. My setup that thru the ce's was stock midpipe/res (at 2") into a 2.25" stromung. My sti now on is 2.25 all the way.
It may throw the ce when it's in 30's or below. So what we do we insulate the pipes with. Scott's thinkin' about how to do that.
Where are we? Agree? Disagree?

My .$.02 I am a happy camper particularly after portending our group well in freeway interactions with M3 guy considering one to autocross/maybe rally with after he dumps the M! He liked the way it went, and agreed as my mc bud, that it did feel a little bit like an italian v-twin bike...a lil'V-8.

Have a good weekend.

[This message has been edited by Greborb (edited December 02, 2000).]

well i just ordered from summit the thermotec wraps. Hopefully it wont be too cold for me to put this on..

Lets see whats happens, I figure it couldn't hurt.....

Js

have any of you checked what code the C.E. light is throwing? I am getting an EVAP code each time and it has come on 4-5 times. It comes on after I drive for a few hours straight but not if I'm just driving around town. I also have not been getting great milage. I have Borla headers (2nd gen.) and they have been heat wrapped since I got them. I'm also using the Borla muffler, a highflow intake, and an AFC. Don't know if any of this info is helpful but I hope so.

Hey John...good idea. By the way, Trey's experience is limited to TX temps I would guess,which may explain why it's no big deal at those temps/latitudes.

Scott's earlier thought of wrapping was probably right!

PS. Donjuan, KC is just as chilly as NJ or OR isn't it?



[This message has been edited by Greborb (edited December 03, 2000).]

Mine threw a "P0420". Carr Subaru's expanation: Catayst System Efficiency below Threshold. Dealer had not seen this code on MY 00&01's.

Has anyone looked at the EGR (exhaust gas recirculation) subsystem as being the culprit? I think there is potential for mods such as headers, exhaust, and/or intakes to have adverse effects on this subsystem depending on it's implementation (meaning Subaru's, if the 2.5L even uses EGR). This in turn could lead to other problems resulting in a CE light.



[This message has been edited by Scottie (edited December 06, 2000).]

1)Does anyone know if the 2.5L has EGR? 2)If it does, anyone know if there is a DPS (differential pressure sensor) to sense the pressure differential between the intake and exhaust manifolds? Also, with MY98-99 RSs using MAFs and MY00-01s using MAPs, their implementations of EGR probably differ some. 3)Anyone know how they differ?

4)If there is a DPS, does anyone know where it's located?

5)Anybody know what the limits are of the EGR valve? 6)In stock form, at high loads, is the valve ever close to those limits? 7)In other words, does it ever come close to being fully open 100% of the time(duty cycle) in order to recirculate the required amount of exhaust gas? The reason I'm asking these last few questions is that exhaust and/or intake mods could push it the EGR system beyond those limits. There are two possible reasons for this. One, by reducing pressure in the exhaust manifold and/or increasing pressure in the intake manifold, you will reduce the pressure differential. The pressure differential is what drives the recirculation of exhaust gas back into the intake manifold. If you reduce this pressure differential, then the EGR valve would have to open further and/or longer to recirculate the same amount of gas. Second, the goal of such mods are to increase power. With increased power comes the need to recirculate more exhaust gas. Both of these things combined could push the EGR system to its limits and beyond, resulting in too little exhaust gas to be recirculated. This would mean higher combustion temperatures which would result in increased NOx emissions. These higher NOx emissions could effect catalytic efficiency and thus trigger a CE light.

Of course this is all speculation on my part.


[This message has been edited by Scottie (edited December 06, 2000).]

I agree with Scottie's concept, which puts us into the church.

At this point after talking with Bob T (Carr Subaru) this am, we and Scott think that it would be good idea to wrap the borlas, in this area, as John is doing. I'm going to wait and see as mine is doing fine now. Guinea pig!

Those Carr guys are great. They'll do mods...it eliminates one variable. They did most of mods on Sean's 2.5 Turbo RS. Forward thinking. http://www.i-club.com/ubb-files/smile.gif

[This message has been edited by Greborb (edited December 04, 2000).]

8)In addition to the impact that some mods may have on Exhaust gas recirculation, has anyone looked at Secondary air? 9)Does the 2.5L even use secondary air as part of its' emissions control?

Depending on the mode of operation, I believe secondary air is pumped into either the exhaust manifold, catalytic converter, or intake. To me, the keyword would be pumped. Reducing backpressure in the exhaust system would make the pump's job easier when sending secondary air to the exhaust manifold or converter. If the Secondary air control system can not compensate for such changes in backpressure, then too much air might get sent to either of those two places. Too much secondary air could cause overheating of the Catalytic converter.

Again, this is just speculation based on the little knowledge I have of emissions control systems in general, not Subaru specific. My main point is that mods, that seem as simple and straight forward as say a performance exhaust, have the potential to mess up systems that aren't often talked about on this board.



[This message has been edited by Scottie (edited December 06, 2000).]

Scottie's lecture series here is very good. Ecu algorithm contraints, whatever they are, and the reality of Drs. Boyle and Charles Laws are key here...to help the ecu believe that backpressures, exhaust temps are within parameters....so therefore in colder climes we wrap the headers to increase the measured exhaust gas temp..Is this your point Dr. Scottie or an easter egg hunt to confuse those of us who don't know what the ecu algoritms/parameters actually are? http://www.i-club.com/ubb-files/confused.gif

Where did Dr. Scottie come from? If anything, I'm usually referred too as Uncle Scottie.

In my third post, my hypothesis is that too much secondary air may be causing one or both of the catalytic converters to overheat damaging it and/or one of the O2 sensors.

If your last statement is to suggest that I might know the alrorithms/parameters actually are, then that would be an incorrect hypothesis on your part (sorry, just trying to play into the Dr Scottie part). Our beloved ECU's have an embedded processor and pulling the code would not be a simple task.

Basically, if the person having the Borla headers put on can't answer my questions, I would at least hope the parties that designed and developed them could.

[This message has been edited by Scottie (edited December 05, 2000).]

although i am an engineer by training, scottie, I want the freekin' thing fixed for my driving pleasure although I share your fascination with the technical parameters --none of which we know -- and expect, as you suggest, that SPO/Borla, the collaborators on the 2nd gen, are suggesting a wrap with advice to follow on what and how. They feel ok 'cause the borlas were designed for the smaller borla cat-back system.

Those of us that actually have the problem, particularly 00&01 with an ecu of greater complexity, want to fix their cars --John, donjuan, myself-- rather than intellectualize it further. So with that kind of balance in this post....it should continue to offer new insights. Capiche or we're on the same page pragmatically opposed.

(edit: add PS)

P.S. That's why this is such a great board --lots of knowledge and creativity. http://www.i-club.com/ubb-files/smile.gif

[This message has been edited by Greborb (edited December 05, 2000).]

All is well...+mpg....no ce...donjuan, john: ok..no ce? All that stuff Scottie wanted to apply can apparently be done more readily on MY99 and below.

I havent received the stuff from summit yet,
The light is curremtnly off, after i go through 1/4 of a tank.

We need tp wait and see

That's it. Be prepared. I'm comin' up on 700 mi with no ce. Had my dashboard all apart converting to amber cockpit and possibly customizing warning lights so ce would come up a dull color...that's a killer distraction when it comes on...

Talked with Scott at SPO Motorsports. He has spoken with borla r&d folks and borla will get back to him. Preliminary is don't wrap the pipes yet...that some tests on an RS w stock exhaust and borla h threw the ce light within a mile!

Oh well i just received the wrap. Too cold to put on the car anyway... I'll prolly still use it. no ce light so far 200 miles.

js

[This message has been edited by john seput (edited December 09, 2000).]

Well I got my headers almost weeks ago. One week later the Borla catback and pulley from SPO. Wrapped the headers the same day I got the cat back. Aprox. 2weeks already: No problems only joy,thanks Scott, also installed my Custom made CAI a week ago without problems.
Driving tomorrow to Cobb Tuning for cams and hopefully throttle body.

http://www.texasubaru.com/12-03-00/andresengine.jpg

http://www.texasubaru.com/12-03-00/andresintake.jpg

Andres

[This message has been edited by AndresRS01 (edited December 09, 2000).]

Greborb,
The CE light being triggered with the headers using a stock exhaust is very interesting. Sounds like it is a design problem and not a flow issue. Unfortunately this whole issue is stopping me from doing any further mods for the time being.

AndresRS01,
That CAI is definately trick http://www.i-club.com/ubb-files/smile.gif Sounds like you're on a roll! Let us know how Trey's parts work with your setup.

Yeah...borla apparently had a similar problem with chevy impalla ss....let's see what their suggested fix might be...this is an easter egg hunt.

Hey AndresRS01:
That's a trick engine bay http://www.i-club.com/ubb-files/cool.gif. And your custom CAI...what have you got an in-line filter or just a screen to grab the big chunks???!!! http://www.i-club.com/ubb-files/biggrin.gif

[This message has been edited by Greborb (edited December 09, 2000).]

Well I have a regular cone filter inside the fender,and made a ram air modifying the inlet under the fog light.

I had the nicest time with Trey today, he's very cool and Knowledgeable. He talk to me and my friend Steve,for three hours about all the possibilities on our cars. The first plan this morning was to do the cams, but after the "class" and a ride in his Cobb tuned RS....no more choice but get head cams and throttle body, which according to him, we all the mods I have already the car will be close to the 210 hp range all motor!
I just have to wait a few more days, probably won't make it to the Car Show this coming weekend in Houston but I don,t care is now or never. I'm going to run out of friends taking me to Dallas every weekend to drop my car.. http://www.i-club.com/ubb-files/smile.gif
We'll see. I highly recommend at least to meet Trey you would not regret it.

Andres

Thanks AndresRS01.

I have had a number of lengthy conversations with Trey and come away very impressed with his knowledge and his demeanor as a fine human being. Given your intake undertaking and interest..have you seen, in Trey's shop, any prototypes of the long awaited Cobb Intake.

[This message has been edited by Greborb (edited December 10, 2000).]

No..but coming from him it has to be very good, you know!

New ce event:
Date:12/10
Outside Air T: 34
Mi. since last event: 800+/-
mpg (last fillup): 25.4

Comment:
Temperature of exiting exhaust seems to be the issue here. When it gets cold...it throws a ce. So there should be ce's thrown.

Borla's opinion now seems necessary. I've been going through Scott Orem at SPO Mtorsports. Scott tells me that Borla has been apprised and will get back to him this week. Stand by.

Any other ce events to report? Outside air temp?

R&D in progress. http://www.i-club.com/ubb-files/wink.gif

Nothing yet

oh well, spoke to soon.
after about 280 to the tank filled up, 35 miles into the new tank CE light came up. This was after running for about 30 minutes.
The engine wasn't cold...

Js

click...it's time for the prescription from borla.....where are you scott?

I think we should test them on a 1998RS (only one sensor). I'll supply the car if anyone else supplies the headers http://www.i-club.com/ubb-files/smile.gif
g0 98RS

I got off the boat , took apart the dash and pulled the bulb.

Well its gone again, after about 1/4 tank through, about 90 miles. Wierd.

Js

I think that it may be confirmation that it will come in colder weather when exhaust temps are below 40 F with the freer flowing cat-back systems. Expect mine to come on. I think it's colder in NJ than OR now...we're in high 30's.

Anyone in warmer states having problems? I will be getting these by January. Living in Fort Lauderdale, we don't get too cold maybe in the high 50's, but not nowadays. Its been like 82 degrees since Sunday. Plenty of rain though.
Zee

im in California and am probably going to end up with the borla headers. ill let you guys know if i joined the FOCEB (fresh off the ce boat?)

Mine CE came on while I was traveling up to Maine last week. I have intake, 2.25 cat back rallispec exhaust and of course the borla headers. I cleared the computer and it came back on while the car was warming up... I didn;t even drive anywhere yet! When I had the code pulled my tech said it was running lean at 3000rpm. (I have no idea how this came on when the car was warming up since the car does NOT idle at 3000rpm). I don;t have the header wrapped yet but I'm werkin on it, I gotta install my S-AFC this weekend too. Does anyone have setting for the S-AFC with intake exhaust and headers? (Yes it should be different that with just an intake and exhaust). I also have this wicked flat spot at 4000 rpm, feels like the engine gets transformed to an old 1800 series old skool sube 1.8 engine that I have in my 87 DL wagon 4wd backroad beater in NY. If anyone has anything that would elp PLEASE let me know
waltsacura@hotmail.com
AIM; waltsacura

Waltsecura:
What year is yours?

Greb.

(edit)
PS. Reason for asking is that MY 00& 01 have more complex ecu algorithms that nobody seems to have deciphered (other than subaru)so AF adjustments could add more variables & difficulties. That's why we're keeping this post open.

[This message has been edited by Greborb (edited December 16, 2000).]

[This message has been edited by Greborb (edited December 16, 2000).]

I'll have mine Tuesday or Wednesday and I am in a warmer climate, so I can let everyone know if I get the CE light. This will be on a MY00 RS in Phx, AZ

Aaron http://www.azscooby.com

Greborb: Mine is a MY01. I think my tech at Subaru wioll help me dial the S-AFC in with the obdII tool, he prolly is sick of seeing me and hearing me complain, so he'll prolly even do it under warrentee. Can I mess with the S-AFC to make the HUGE power hole at 4000rpm-4500rpm go away? Well, please keep this post going, maybe we'll get some answers...

I Know SOA checks this out from time to time, lets hope they are werking on this as much as we are (Of course that will prolly never happin).

Yeah Walt....I think everybody involved would like to fix this problem...I'm working on it with my dealer too. Although I don't have any AF adjustment gizmos...I may have to get one.

Patience.

Well, I'm werking hard talk9ing to people, fropm the information that I have gathered, I'm being led to believe that the culperet may be the front o2 sensor. The damn wide band o2's make it impossible to use a standard AF gauge...so we must find another way.

BTW: I just filled up with 87 and wailed around Ambler for a few hours rippin the hell out of my Blizak MZ-01's and it only hesitated on me once or twice and very slightly. My CE light remained on and the hole in the power at 4K rpm was still alive and well. I'm being a slacked and not installin the S-afc until I get to western NY where I have a nice warm shop with a heated floor, every tool known to man, and several lifts to choose from. I'm just not concerned enough to do it in my cold ass garage with no tools down here in Ambler.
Looks like we'll have snow for the next week or two in NY, *a slidin we will go...*

I've been persuaded to go with coating my headers rather than wrapping them, anyone know where in the Philly region I could get them coated for under a million dollars?

Just my $.02...

I have a 99RS with the Borlas and a 2.25" cat back.
Ive been driving alot in this cold Jersey weather with no ce light.

***I have the stock intake still***

Just curious who out there is getting the CE light with an aftermarket intake and borlas?

Waltsacura:
Your experience ties out with those of us in colder climes throwing the ce rather than the front o2 argument. Trey seemed to think it might be front o2 but didn't have any hands on experience with the problem at all in TX (despite many borla header installations with cat-backs), a warmer area. RichL has a '99 with a different ecu so
the header and low EGT remain the prime possibility I think. Other opinions?

I don't recall reading posts about the CE light with the 1st-gen borla headers?? Of course i don't think alot of people used them either. What are the major differences between the new headers and the old??

Waltsacura wrote: "...When I had the code pulled my tech said it was running lean at 3000rpm...."

If an O2 sensor is not at the correct operating temperature, it will most likely give a false lean reading. This fits in with the theory that the Borla headers result in lower exhaust gas temperatures downstream. However, this would be the case throughout the rpm range, so it does seem strange that your tech gave you a specific rpm.

This may be detrimental to engine power, but has anyone played with the spark plug heat ranges? I was wondering if one range hotter than stock might actually help with the gasses.

Gary

Gary,
Go to the NGK web site. It has some good technical information about heat ranges and what affects they have and don't have.
www.ngksparkplugs.com (http://www.ngksparkplugs.com)

One step hotter will result in a spark plug tip temperature of about 70-100 degrees C hotter. The keyword here is "tip temperature". I don't think the higher thermal resistance of the hotter plug will have that larger of an impact on your EGTs.

[This message has been edited by Scottie (edited December 19, 2000).]

It's back...
Nativo has the generation 1 headers and he has the problem.

Js

You could actually hear the car running lean at 3000 rpm and once you held it there it would richen up a bit. Growing up in a collision shop I kinda have the ear to hear stuff like that. It may be doing it all over the rpm range, but that's just when I heard it...
Going to the dealership tomorrow at lunch, I'll try and post my exact CE code tomorrow sometime...
I'm running the NGK plugs that are supposed to be in the car, unlike those damn champions (I tried my best to remove every piece of my car that was made in the US and replace it with a part from Japan).
I was wialing around in the first real snow that we got here in Philly tonight, lots-o-fun, run decent, CE light still on...

Paul;

Are you hearing it run lean, or are you hearing the effects of running too lean (i.e. knock/ping)? Could you describe the sound?

I don't have the Borla headers, nor has my CE light gone on, but I have been getting some usual sounds starting around 3000rpm on colder days. The sound is something like valvetrain noise from an old air cooled VW engine. Other threads list several possibilities for the source of this noise, but I need to do some more diagnostic work before drawing any conclusions.

Spoke with Scott (SPO Motorsports) this am after sending him this thread. He is in touch with Borla. Apparently they are testing but having problems simulating ce 'cause of location (So CA & higher temps).

Yup. Sure is although it's been milder here (early 40's) so no ce.

I wonder if anybody has borla header on where it's really cold like Alberta;
Western/central Canada; northern VT, NY, ME? In theory they wouldn't be without the ce light on.

[This message has been edited by Greborb (edited December 20, 2000).]

It wasn;t knocking or making any ping sound, you could just tell that the engine sounded a little less lubricated I guess. I'm not really sure how to describe the sound. I'm going to pull my plugs when I get home to NY and see whatthey lool like.
My light came on when I was in Conn. Stayed on through ME, MA, CT, NH, NY, NJ and it's still on now that I'm in PA.
The temp gauge I have in my room indicates that the coldest that it has been round here in the last week is 18 degrees.

Anyone (SPO, Trey) wanna fly into Philly and take a look at my car? Anyone know where I could get it looked at round here. By looked at I mean tested with a gauge designed to read the AF mixtures of a wideband O2 sensor?

Yes, this problem downright blows... someone please figure it out.

BTW: I'm trying to get over to my dealership to get them to pull the code, but since I wer from 8am to 6pm it's kinda tough, I'll try and go over on my lunch tomorrow.

waltsacura@hotmail.com
AIM waltsacura

Walt..., Donjuan, and John:

Just went to borla site (www.borla.com) and filled out one of their customer service forms:

"There are many of us in the Impreza Club of North America who have installed your new header or are considering the header for the Impreza RS. Those of us who have installed the header like it with one exception. In cooler climates, the "check engine" warning light is coming on. The consensus is that that exhaust gas temperatures are below the ecu thresholds and the warning light is appearing. Scott Orem, SPO Motorsports, informs us that you are aware of the problem and working on possible remedies. We would appreciate hearing from you about the possible remedies as soon as possible. I believe a number of board members are awaiting the outcome here before puchasing a header system.

Please advise.

Thanks,

Bob Broberg"

Let's turn the heat up a little with one of you doing same and providing them with this thread, which I did not. I shudder at the thought of the joke being on us and this problem getting moldy in somebody's in basket. Colleagues unite! http://www.i-club.com/ubb-files/mad.gif

Thanks guys...R&D http://www.i-club.com/ubb-files/wink.gif

[This message has been edited by Greborb (edited December 20, 2000).]

This is aggravating.

Have any of you guys, with the CE light, pulled your front O2 sensor and looked at it?
Did the shield over the sensing tip have a black sooty coating or powdery white coating?

Anybody know the exact material the stock headers are made of? I'm looking for more than just steel or stainless steel. Example: The Borla headers are 304 stainless steel.

Forwarded the thread to Borla with similar questions...will post if I hear anything.

I just ordered my headers today, hopefully theyll be here soon. I'll post when I get them and if I get a CE light. Hopefully the climate here in CA will not permit it to light up.

[This message has been edited by Andrew (edited December 21, 2000).]

I was thinking originally that maybe some chemical that was on the headers blew out the 02 sensor but... the problem is intermitent.

I have on order an AF with 02 and egt once i get it in and installed I'll let all know whats going on.

Js

Well I got the check engine light tonight. It was mid to high 50's here in AZ. The car had been sitting for a couple hours in the cold, I started it up and drove 3 miles or so and I got hit with the light. It is on MY00 RS. I had about 70 miles with the headers before it came on.

Borla should be able to recreate it if I got one with the temp in the upper 50's, I know it gets at least that cold in CA...

Aaron http://www.azscooby.com

Nothing from Borla yet.

AaronB's in AZ does argue for Borla to "turn to" and let us know....have heard nothing from them and mine just came on again on a ski trip (elev. 4500, T=30 F).

[This message has been edited by Greborb (edited December 22, 2000).]

Another possible variable. New post "Engine Light?" indicates problems with ce light & Larry's Intake. Anybody with problem have CAI into fenderwell like Larry's besides me?

I would be interested to hear more about this issue.
We have never had this problem happen here in oz with our system, nor has it appeared in the systems we have shipped to the US or other O/S countries.
Kyle from CTC (dallas) has not had it happen either.
Please also e-mail me direct if you have any feedback.
Brett

On second thought, CAI (fender) is not a contributer.....Borla, Borla, Borla.....where are you? Should we tell our brethren to postpone purchases 'til we hear from you.......??

[This message has been edited by Greborb (edited December 23, 2000).]

Greborb,
I certainly aint gonna buy one until Borla resolves this issue. Don't need the headaches http://www.i-club.com/ubb-files/frown.gif If this goes on for too long I'll consider getting the MRT setup instead.
-Shawn

The MRT guys are tuned into this post wanting to sell you one.......earth to borla...earth to borla... http://www.i-club.com/ubb-files/confused.gif

On again...T=34 F.....a brilliant christmas ce light http://www.i-club.com/ubb-files/frown.gif....earth to Borla. Will have dealer check O2's later this week.

I definitely want a resolution to this too. I'm looking for headers and figured I'd get the Borla ones. This issue, if it's temperature related, like lower than 40f I'd get them. I live in Puerto Rico so even when it's "cold", it's still in the high 60's low 70's. If it's not temp related then I'll get another header.

Well, I don;t know where my pther poste went that had my alpha numeric codes in it, but I'm home in NY and The codes are down in Philly, I'll get tham and repost tomorrow nite. I think it was a P301 code and a P103 code. I called trey and left a message, I supposen I'll call him on wednesday and see what's up. I had a cylynder misfire while at idle (prolly just an engine cough cause it didn;t throw the CE light till I was doin 65 down route 611) The other was basically the front o2 running lean. I'll write borla when I get nack home, hopefully we'll all get somewhere before our cars are all 10 years old.
My tech is werking on the problem now too, he's trying to see if it's a problem with the front O2's, I he told me that SOA may be doing some sort of a recall thing on them.... I'll keep you informed as much as I am.
*dreams of 300 hp interupted by dreams of a 180hp RS with NO DAMN CHECK ENGINE LIGHT!*

Hmmmm Grebor remeber when I started asking what the part numbers were for the front o2?

I based that assumption on the recall.. Anyway I sent email also to Borla... nothing yet

When I went to Rallispec they said the rear sensor was throwing the code.

More and more frustrating...
Js

umm...just another pondering...could the O2 sensor be picking up the temperature of the pipe itself and not the gasses? Could be way off, but it's just a thought. Has the problem occured with a new O2 sensor installed?

Gary

Is this a problem for all years or only my2000 on? I am hoping to put them on my my99, but I'd hate to have to deal with the CE light here in chilly Maryland.

Dan Z.

You guys could be on to something with the 02 sensor specific to MY00's etc. I had mine replaced at the dealer right after I bought my car. The tech said that the diagnostics were showing a funny reading from the O2 sensor so he decided to replace it (i'm assuming it was the front one) I believe that others have had problems with the O2's on their MY00's also. Whatever its worth.
-Shawn

Thanks Walt. When I spoke with Trey some time back, he thought it might be the front O2 sensor. Borla, so far, has been disappointing with their lack of response. Hang in there.

does anybody know the part number for the 02 sensor?

Js

john seput wrote: "I was thinking originally that maybe some chemical that was on the headers blew out the 02 sensor but... the problem is intermitent."

I don't think that simply because the problem is "intermittent" that chemical contamination of the O2 sensor can be ruled out. Contamination does not always result in a single catastrophic failure. The problem could be a combination of things, say temperature and contamination, resulting in intermittent CE light.

Silicone and O2 sensors don't get along from what I've read. The Mandrel bending process involves lubricants. If any of the lubricants contain silicone and are not fully flushed out of the headers, then it could be a possible source of O2 contamination. A white powdery residue on the O2 sensor's shield is a sign of such contamination.

P.S. I'm also looking at the Borla headers, but won't buy until I'm satisfied all such problems have been resolved.




[This message has been edited by Scottie (edited December 26, 2000).]

Well, if anyone wants to send me a set of headers I would be happy to tell you if there are problems. Considering it was -21F when I got home at 11pm on Christmas Eve, I think that would be a fair test to see if it is indeed temp related. HeHe.

Christian

Where is the fron O2 sensor located? In the first cat? Somebody take a look, I would if I had the Borlas. I'm gonna get them real soon even if there is no clear resolve to this issue. If no one has taken a look at the sensor by then, I will.

I've been following this post from the beginning because I am interested in getting the BORLA products for my MY00 2.5RS.

From reading and studying the posts, and talking with other people, it seems the general solution to such a problem is as follows:

- BORLA products work with BORLA products. If you're going to get the BORLA headers, save up enough money to also get 1) them heat-wrapped 2) the BORLA cat-back exhaust system.

- ECU reset after full installation.

- Install all BORLA components at once.

This is what I have come up with as my work-around to the CE light.

One example of this solution being used is AndresRS01 - the owner of the NA monster Impreza. I believe he got the cat-back exhaust, and heat-wrap for headers when he got the headers - all as one big package. Whether he got them all from the same vendor is unknown to me.

Please give me feedback and suggestions. I want this problem solved just as much as any of you.

Again... this is just my idea. http://www.i-club.com/ubb-files/wink.gif

Cheers,
Tom Richardson, Jr.

I have the wrap just not installed yet. Too cold. Hopefully when the guages come in I can do it at Rallispec in a garage.

Until the ....

BTW no light on a whole tank of gas, different gas though....

Js

[This message has been edited by john seput (edited December 26, 2000).]

Narso,

I have a MY99 and also have the Borla Headers and have experienced no problems what-so-ever. It's been 0degrees when I was running them and it's been almost 60degrees also and still no problems. I also am at an altitude of 5400ft and am currently running stock intake. I've run 87 Octane and I've run 92 Octane. And again no problems at all. I am very pleased with them and catch myself rolling my windows time from time to time just to hear them... http://www.i-club.com/ubb-files/smile.gif


Oh, I also commute 45miles one way to work every day sometimes doing 65mph sometimes 85mph. Again, no problems. I ran it hard on the 24th doing all the last second shopping with all my tools in my trunk (and my kids) and again not one problem, burble or CE light.

So far, I love it!

Andreas01's car (MY01) not only has Borla headers and cat-back, but highly ported and prepared Cylinder Heads, Cams and over-sized throttle body and he still doesn't have a check engine light. My point being that I don't think the ECU is so sensitive to the changes in backpressure or temperature that it's detecting the Borla headers and throwing any codes.

I'm still under the belief that the front O2 sensor, and possibly ECU if that falls under a Subaru-recognized recall, could be at fault. Even though some people say the second O2 sensor is giving a code, that could be due to the fact that the front O2 sensor is not reading properly, causing the engine to run abnormally rich/lean at idle and at cruise when the ECU is in a closed-loop (constant O2 monitoring) mode. This would cause the second O2 sensor to throw a code, as well as a reduction in gas mileage, sulfer smell, and quite possibly performance problems due to the spark plugs getting fouled from rich mixtures.

Unfortunately, until we get a problem down here, I'm at a loss as to how to diagnosis it. We've installed nearly a dozen GEN.2 Borla headers on MY00-MY01 models with ZERO problems.

Best of luck,
Trey
CobbTuning.com

My brother's '01 rs has a stromung dual tip exhaust, borla headers, and a cone filter on the throttle body. Here in quebec, it has been -20c for the last few days. 500km of driving in the last week in temps ranging from 15c down to -25c and not a blink of a CE light. Greborb, I would be very curious if the CE light goes away after replacing the front O2 sensor.

Has anyone measured the current to the front O2 sensor's heater (I am sassuming all model years front O2s are heated versions), both before and after install of the headers. I remember seeing a schematic for the MY99 unit where I believe the return for the heater is through the body. Which would mean the return is through the headers at least part of the way. If the resistance of that return path has increased for any reason, the heater may not be getting enough current to function properly.

I know, its a long shot, but I've seen stranger things happen.

This is part of the reason why I asked if anyone knew the exact materials of the stock headers. EDIT: From looking at the picture of steve_d 's header from his "Pictures of my VERY cracked header" topic, I would have to say at least part of the stock header is Aluminum. Aluminum has an electrical conductivity much greater than that of mild steel and mild steel is about six times more conductive than 304 stainless steel if my memory serves me right.

Also, are you guys all replacing the gaskets or using the old ones? Are you cleaning up any corroded surfaces that could affect this return path?

The current to the front O2 sensor heater may be reduced just enough that the problem only manifests itself in colder temperatures.

Also, I believe the o2 sensors heater is not always on. Does anyone know for sure what inputs the ECU uses to determine when to turn the heater on and off? Is it just coolant temp, or others?



[This message has been edited by Scottie (edited December 27, 2000).]

Ok, got off the phone with my dealerships parts dept. The front sensor is an A/F sensor according to there manuals, the second sensor is a standard o2 sensor.

Part #'s are 22641aa011 and 22690aa420 dealer quoted $141.00 each Subaruparts.com has them for $107.00.

I haven't thrown a lite in a week lets see what happens. On a side not my A4 just threw one this morning (no mods).

When it rains it pours.

Js

I already had my front O2 replaced... I didn;t have my headers when I had it replaced... but now I have the new o2 sensor and a nice bright CE light. I had the dealership clear my codes when I had them read it of course, it seemed kinda weird NOT having a CE light, I guess I'm used to it now.
Has anyone with a ce light wrapped their headers yet? I think I['m going to try and find some wrapping locally and wrap them... as soon as I can find some time...
Not too many posts get over 100 replys... goes to show you how much of a pain in the ass this whole thing is I guess...
I'll go to the dealership some time this week to see if my tech has come up with anything...
My previous post is incorrect, the second code is not a P0103 (since one doesn;t even exist) I think it may have been a P0106, but since I lost that little piece of paper I wrote it on I'll have to go back to the dealership and get him to pull it again... oh well, at least I'm over there once a week so I don;t have to go out of my way or anything...:->

Damn Car

Just returned from a trip to BC. The bloody light came on just as I was arriving in Vancouver with not so great mpg en route. Reset it and returned with pretty good mpg.

Have read the posts and think, based on Scottie's & Trey's contributions, that the O2's are strong candidates again (although Walt has replaced his!)for what appears to be a problem unique to '00's & '01's. If the pattern continues, it should reappear in a day or so.

Am going to ask my guy, Bob Thompson at Carr Subaru, to look for the residues Scottie described, review this post, call SOA, and replace sensor (front).

I would like to pleasantly surprised with a response from Borla......... http://www.i-club.com/ubb-files/confused.gif

Am still persuaded that we will get at this and appreciate the value of the board/opinions. Can you imagine going through this kind of c..p solo and the exposure to throwing $ away.

Is it possible that people are damaging something (front 02 sensor) during the installation process. Trey says he has had no problems at all with dozens of installs. Don't get me wrong, I'm not calling anybody incompetent or something, I just know that Cobb most likely does the installs on a lift, whereas us average shadetree mechanics probably wriggle under the car on jack stands or the like. I know on my car the wiring to the sensors are JUST long enough, maybe people are damaging them?? I believe they are fairly fragile...

Remember, Walt stated his O2 sensor was replaced before he put the headers on, so contamination from some substance on the inside of the headers is still a possibilty. Also, if the problem is somehow related to the O2 sensor's heater, replacing the sensor probably wouldn't solve that problem either.

There seems to be a pretty good backlog for these headers. The local performance shop I deal with is still waiting for their headers that they order sometime ago. Until they get a set, I can't due much more than speculate. Besides, I have to take care of my blown head gasket first.

When Walt said: "Is it possible that people are damaging something (front 02 sensor) during the installation process. Trey says he has had no problems at all with dozens of installs"......a bell went off. Mine was installed with much ado & banging/clanging in a garage rather than on a lift by pros.

So we have possible damage at install as well as residues from the header itself.

I love my 98' i have a 2.5" tail pipe and the new Borla header with 6,000 miles with no problems. has anyone with a 98' had a problem?

Mine was put in by Rallispec, and there was no problem installing..

I do remember the smelling the headers burning something off though.

Js

I installed mine, but I grew up in a body shop... so I kinda know what I'm doing. The only problem was removing the nuts and bolts from where the old header bolted onto the cat section, those bolts are ruined when you take them off. Other than that the install is quite simple. I'm going to go out in my car and get my fuel book, i'll figure out my mpg since this whole thing and post later. I'll find some wrapping this weekend, but for some reason I doubt highly that it will go away.

Check out this link: http://www.i-club.com/ubb-files/Forum24/HTML/000865.html

looks like it may not be the borlas

hmmmmmmmmmmmmmmmmm

Js

Mine has come on again after about 500 mi from last reset. Trying again to sort through all the info....and...it's beginning to look like a bad o2 as outside temp was in the 40's.

Does anyone have ideaS as to why some peoples light comes on and stays on (like mine) and why other people can drive around for hundreds of miles woith no problems? Could thid be a different problem?

I would get the light after driving a few miles in low 50 or high 40 degree whether. I would reset the ECU and it would just come back. I took the headers off today and I will reset the ECU and see if I am still throwing a code. If so I am going to the dealer to get a new O2 sensor. I am not putting the Borla's on the car again though, I decided to try a different way to make power http://www.i-club.com/ubb-files/wink.gif

I will miss the sound though http://www.i-club.com/ubb-files/frown.gif

Walt, I think others (moi etc.) are resetting ecu's. I think Aaron B's plan will help determine whether borlas are source or not. I'd be curious to know how he plan's to recoup the 7 or so hp & torque.

Borla's lack of response to any of us suggests that either they can't figure it out or that they know their product is the problem. Unfortunate....I guess customer relations & sales to Impreza owners are a pee hole in the snow in the whole cosmic scheme of things.

What I don't understand is why Cobb Tuning has had no problems with this. Texas has had temps low enough to be in the range where others have had problems. What are the odds that most everyone who has used the headers just happened to have a bad O2 sensor, but none of the Cobb customers did?? What is your secret Trey??!! http://www.i-club.com/ubb-files/biggrin.gif

I think AaronB and I will be testing out some theories here. We are going to put the headers onto my car at some point here and test between the 2 cars. His had the headers brand new and got CE lights. I will be putting the headers on used and we will see what happens. Both cars are MY00's.

Aaron's going to be putting on a turbo kit to make up the lost power....

-kastle

The difference between the cars up here and the cars down by Trey. They oxygenate the piss out of the fuel up here, could this be a cause of our CE light? The temps may be relativelt close, but not for any length of time. My ce light didn;t come on until I had the headers on and was driving around in 50 and below temps for several days.
When I reset my ecu it doesn;t matter, the ce light comes back within just a few miles of driving. I'bve reset my ecu over ten times and it still just keeps popping back up right away.
What we need is some people to do some more extensive testing. We need someone to do something and have the damn light go away. I'm ordering some wrapping tonight although I'm not sure when I'll be able to put it on. I have an fuel mixture sensor (aka o2 sensor) on order at my dealership and he's making sure it's an o2 sensor out of the new batch, aparently they are changing something with the o2's. I would install my S-AFC but it won't make a difference since the fuel maps in the ecu are set to a fixed position when the ce light comes on with my code.
We need to do something and somehow get a response from Borla, when is their home office and who on this board lives near there, someone needs to knock on Mr. Borla's door and 'motivate' him.
From the time I clear the ce light to the time when it comes back on my car has significanly more power, this really sux, a mod that I bought to make my car faster and sound better actually makes my car slower... oh but it does make it sound really cool... damn it, I'm starting to feel like I have a honda now...

Paul;
waltsacura@hotmail.com
(yes I know, I did used to have an Acura, but now I can afford to have a cool car... it's just a broken cool car)

Well a few things to say:
Tonight the temp. is going down to 25's, hopefully my light won't show, I don't have answers, but being one without problems maybe give you some "lights" http://www.i-club.com/ubb-files/smile.gif. Got my headers first(from SPO Motorsports), drove with them a week, then the day I installed my Cat back , wrapped the headers, still no light, also installed a custom made cold air intake with a 3" pipe going down to through the fender and a cone air filter at the end.,finally installed pulley and took the car to Cobb Tuning to get heads, cams and throttle body upgraded.
My car is pulling real hard and no light is on yet(6500 miles).I hope tomorrow's low temp won't affect my baby. Just remember that one function of the wrapping is to keep the gases warm while they flow through the pipes.

But!!!! Now the reason I'm writing here again is because I just got a call from my friend Subpreza, his CE light came in, he only has a cone filter directly on his throttle body and a very large and loud Apex-1 exhaust I think. He drives a MY01 RS 2000 miles on it.

So...may not be Borla related!!!!! http://www.i-club.com/ubb-files/smile.gif

Andres


[This message has been edited by AndresRS01 (edited January 02, 2001).]

Walt,
The fundamental difference between yours and my experiences is that after a reset, mine will go at least a tankful before it comes back on. Also have 10% ethanol gas. Am wondering whether there is a progression of o2 failure whereby yours is further along and mine will be like that soon ( although my '01 has over 12k mi with 3.5k mi since the borla was put on). I'm with you regarding borla. It is frustrating 'cause the car is running rich and performance seems down.

G.

celightmare@bldgpreservation.com

Well guys, I'm out here in CA and I'm putting on the headers tomorrow. I'll be sure to come back to give you guys updates on CE or no CE. I'm very much hoping that it wont come on...

Edit:
Has anyone with who has gotten the CE light bought a new O2 sensor and still had the CE light? I havent had time to run through this entire thread-my apologies if this was covered already..

[This message has been edited by Andrew (edited January 03, 2001).]

Well, I put a new battery in last week (reset the ecu) and so far a tank and half of gas no CE Light. Haven't had the time to wrap the headers as of yet, still have on order the egt and the a/f guages, and now I have an o2 sensor on order from subaruparts.com. I hope to have this figured out soon, but know I have no light..

Weird, the car still seems a little weak though.

Here's some good reading for you guys.
http://www.asashop.org/autoinc/june/Tech2tech.htm

It talks a little about O2 sensor heater issues.

John's latest post, about changing his battery, could fall along these lines. I know my stock battery doesn't crank all that well when it's cold. A weak battery, cold temperatures, increased resistance in O2 sensor heater's return path and/or cooler exhaust temps due to the Borla headers could all be working together keeping the O2 sensor(s) below their proper operating temperature.

Quick review:

Ohms law v=Ri or i=v/R

Lower voltage means less current, keeping R the same. In our case R is the resistance of the O2 sensor's heater circuit.

power=iv

Less voltage means less current. Resulting in less power. Less power is less heat. Both the lower thermal resistance of uninsulated Borla headers and colder outside temps result in cooler exhaust gas temps. Thus more power is required for the O2 sensor's heater to achieve the same operating temperature.

John, did you happen to measure your old battery's voltage versus new battery?

Cool, I bumped it to page 4!



[This message has been edited by Scottie (edited January 03, 2001).]

First I want to say what a great forum we have here...this is a very interesting topic

I say it's the damn MAP based '00 and '01 EFI system that is the root of the problem. How does anybody expect the ECU to work correctly with high-flow exhaust and intake? I assume that our MAP based ECUs have a fixed VE table to determine A/F ratios. Any change to the VE of our engines, should in some way screw things up. Notice how none of this is happening to the MAF based 98 and 99 models? Air temp (intake and ambient) is also used to calculate A/F ratios, so this could be why more people are seeing this in colder climates. It would explain why the codes that are showing are A/F related (lean/rich..bad gas mileage...etc).

Now, Trey said something interesting that he has seen zero problems on the systems he has installed....that is interesting.

Trey, how does the MAP ecu cope with changes to VE (headers, cams, exhaust)?

Just thinking through my fingers...
-Rob

John,

$226 for one!

The thing that is bewildering,as Rob mentioned, is why Trey has had no problems. http://www.i-club.com/ubb-files/confused.gif

We bantered around about TX temps vs. other more northerly points, but Aaron, I believe, threw a ce in a warm climate. I thought for a while that it was Trey's fastidous and careful installs. If Rob is correct....then looks like we may be putting the stock headers back on unless Scottie comes up with a way to trick the electic system....time for a shot of Tequila!

Borla needs to get in on this...many people are already holding off their purchase until this is sorted out. Maybe they just don't care...just DO NOT CARE about their paying customers. Maybe they just don't care that people are saying their products apparently don't work without CE lights constantly. Are you hearing this BORLA?? I've forwarded them this thread 3 times now and nothing...I REALLY would like to hear what they have to say about this.

Yup, borla needs big heat. I've already let Scott at SPO Motorsports know. I bought mine from them. Anybody who bought borla from Scott, send him an email. Presumably, Scott worked on the header design with borla.

Will check with Carr Subaru tomorrow to see what they learned from borla.

Scottie, our resident engineer, has again given us excellent food for thought.

Met with my mod friendly dealer this am to price O2 ($226!!!) and get opinions. They've had 3 come in with ce light issues over the past few weeks. Two have borlas (and are '00 & '01's)and one has stock exhaust while the other has a cat-back system. The other, a '99 I believe, threw a different code, af problem rather than cat converter.

Dealer is going to call borla as I reported that borla was not responsive and there were some po'd owners out there. The dealer is interested as they have a business relationship with SPO Motorsports and could be installing borlas. He doesn't believe it's a malfunctioning O2, but rather related to the borlas and threshold issues, which, in a way, ties out with Scotties technical articulation.

[This message has been edited by Greborb (edited January 03, 2001).]

Scottie, I have the performance gauge pack, it has a voltometer (sp). The stock battery was around 13.5 14 when at a fast idle or moving the new battery is at 14.5. Every time I've CEL'd it has been while driving not at idle which on both batteries brings the idle down to 12v (underdrive pulley).

The new battery is an Optima Yellow Top.

Greborb? 226 is that for both? SubaruParts has them for 107 each (havent gotten it yet though)..

Cool maybe it is the batt?

Js

[This message has been edited by john seput (edited January 03, 2001).]

I just emailed Borla myself. BTW, It this problem may not be specific to just the Borla Headers, someone with MRT has the CE problem also. http://www.i-club.com/ubb-files/Forum24/HTML/000698.html
This is bumming me out. I was really hoping to get these headers soon http://www.i-club.com/ubb-files/frown.gif
-Shawn

Rob has some very good points. There is no way for the stock ECU on MAP based MY00-01s to correct for changes in VE. It could very well be that this is part of the problem. However, the reason I think this hasn't been talked about all that much in relation to this problem is because of the numerous CE lights in colder temps as compared to warmer.

That's why more of us need to get some form of OBDII scan tool. I plan to get the Ease Scan tool software as soon as I purchase a Notebook PC. The data you could collect with such tools could provide considerable insight into this problem.

I believe when ever an emissions related DTC (diagnostic trouble code) is thrown, a freeze frame of all engine parameters is saved. With an OBDII scan tool you could retrieve and view that freeze frame. With the Ease scan tool, hooked up and running, you can set it to take snap shots automatically whenever any DTC is tripped. And there are a ton of other ways to put such a scan tool to use, which has me thinking to myself, "What am I waiting for, just buy a freak'n Laptop".

quick ?
How many of you that are throwing CE lights have larger than 2" exhaust at any point? Just wondering. After hearing the MRT's have expierenced a similar problem I'm a bit worried. I'll have to wait and see.
Aaron

How do you connect the laptop to the OBDII? I have a few ones lying around. Does the software have the connector to do it? I'm still hell-bent on getting the Borlas so I'd hook one of the laptops to the car if I got a CE light and this issue didn't come to a resolution by then.

Here's the link to the Ease web site.
http://www.easesim.com/

Yes there is an interface that connects to your PC and your car's Diagnostic port.

There are other software based scan tools as well. You could do a couple of searches through these forums, particularly the old Technical forum.

I believe on Glenn Wallace's New Impreza site there is mention of free shareware coming soon for this purpose.

Mods that might effect:
Ralispec Intake
Ralispec Apex-I N1 2.5" catback exhaust
SAFC
Borla's

But still no light,

I just got them installed today and I LOVE the sound! I'm gonna go to the Borla catback though as this thing is way too loud (NO not for me, but the cops). I put it on at 10500 miles on a 00RS Sedan. My other mods are Stromung midpipe hooked up to blitz nurspec, and a larry ganz intake. I'm very much hoping that I dont throw a CE Light.

Too loud even with the Stromung midpipe?! (which supposedly silences things a bit) http://www.i-club.com/ubb-files/eek.gif
Niiiiice http://www.i-club.com/ubb-files/smile.gif

Just a note, AaronB took off his Borla pipes and sold them to me(I haven't put them on yet). He put everything back stock (intake, exhaust, headers) and did a ECU reset and the CE light's still coming on. 3 ECU resets, 3 CE lights since taking the headers off. He thinks the o2 sensor is blown and was about to call the service dept. @ the local subaru to see about getting it looked at and determine what code it's throwing.

We are planning on putting the used headers on my car tonight and seeing what happens. It's my belief that I won't get a CE light. The reason is that I think anything that was on /in the pipe has burned off already. Maybe I'm right, maybe I'm wrong. I'll see soon enough.

kastle
<a href="http://www.azscooby.com" target="new">azscooby.com</a>

kastle,
If your suspicions are correct, thus pointing towards contamination from the headers, then AaronB should make sure he gets a look at the O2 sensor(s) before they are replaced. Pictures for us to see would be nice too.

[This message has been edited by Scottie (edited January 04, 2001).]

Scottie pecked out:
There is no way for the stock ECU on MAP based MY00-01s to correct for changes in VE. It could very well be that this is part of the problem. However, the reason I think this hasn't been talked about all that much in relation to this problem is because of the numerous CE lights in colder temps as compared to warmer.

Hmmmm, wouldn't the colder temps also increase the car's VE too. The combo of both might push the VE too far out of range. Just a thought.

Tony

no there is air density correction, so it shouldn't effect VE. It is possible that the VE table is more off for colder temps.

If anybody has one of those nifty scan tools, they could take O2 readings stock and w/borla to see how much difference there is...just another though

Residue inside the pipe causing problems is a possibility. I'm still leaning torwards a front O2 sensor failure but we'll see.

I finally got a hit down here in Texas for a MY00 w/ check engine light. He's had the Borla headers on for about 1-2 months now, but we just had a week of very cold weather. He's bringing me the car this Saturday for me to scan and we'll see what we can determine. Hopefully it's something useful to this particular problem and not something unrelated like a loose connector.

As for how the MAP ECU copes with changes in VE, from my experience it seems to try and adapt quite a bit. That might be part of our problem, the ECU tried maybe too hard with it's long and short term correction maps. It's definitely not working off just a basic hardmapped VE table w/ some simple corrections. It seems to act much more dynamic than that. I could be wrong, but they just don't respond the way we would expect if it was a more simple VE-table mapping system like you find on other MAP-based cars. This seems more advanced and to be honest with you, I hope the new WRX w/ it's MAF-based system is more like the MY99 style of ECU.

Cheers,
Trey
CobbTuning.com

Trey,

In general, how is it possible for a MAP based ECU to detect changes in VE? What sensor inputs could give that type of information? The only thing I can think of is that maybe it compares previous MAP vs RPM vs TP readings to current values. But that would require a bit of memory, and any reset would kill that.

But I don't think it's possible (or probable that Subaru put that much development work into it).

Damn we need to talk to a Subie programmer!

-Rob

I am having the CE light problem aswell. I have pulled the front 02 (A/F) sensor and it is covered with black sooty crap. Sensor should be a white/grey color. I agree with Trey on the sensor being fouled by carbon deposits as I had a civic with b16 swap and chipped computer give me the same problem. No ammount of tuning on the 'ol afc could fix the problem. Fouled 02 = incorrect sensor output = CE light.

By the way, I have Rallispec intake, New Borla header, and Apex N1 catback...

Guys,
Check this out. I got a response from Borla. Here's what I wrote:
Have you resolved the issue concerning the Check Engine light coming on with your headers on 2000 and 2001 Subaru Impreza's? I plan on buying them very soon, but am holding off my purchase until this issue is resolved. Any info would be much appreciated. FYI, there are a lot of people out there with the same concerns as myself. Check out this discussion on the subject that is ongoing http://www.i-club.com/ubb-files/Forum24/HTML/000546.html

Their response:
yes we did solve the problem...try comp design @ 8014849812...they have them in stock

Whatever its worth.
-Shawn

Holdonasec. This CE light is being triggered on ALL Imprezas, or just the MAP-equipped ones? That would narrow down the source of the problem, I'd think...

I'm considering the headers but I don't want any CE light crap. Had enough with the ABS light coming on already...and I haven't even screwed with the brakes!

"Yes it's fixed, here's where you can buy it..." What kind of response is that?? I'm getting very disappointed with Borla...

O.K....but what's the fix...a revised header?

Vision:

Borla sales/marketing guy thinking out loud in his cubicle:

"Let's see...maybe 300 potential buyers=say $9000...chump change..no customer relations expenditures emails, calls...we broke our picks....so what"

As kastle stated I am back to stock, after multiple ECU resets last night and today, my CE light never went off. I went over to kastle's place and helped him install the used headers. So far no CE light on his MY00 RS.

On my drive home I noticed my CE light had went out. Hmm strange. Whatever code I was throwing seemed to have stopped after 20 miles or so after multiple resets and reverting to stock components. Temperature was about the same as when I was getting the CE lights.

I did not make it to the dealer as their "Subaru Tech" is out of town until the 12th or something crazy like that. Noone else can work a scan tool I guess http://www.i-club.com/ubb-files/rolleyes.gif

I will keep you all posted if I have anymore problems.

Aaron http://www.azscooby.com

Well, I just REMOVED my Borlas and put the stock headers back on. After driving around for several minutes I saw NO CE light. I then called my friend Steve to tell him my light was gone and all the sudden while I was driving rather slowly the light once again illuminated my interior.
I have an o2 sensor on order and Subaru is footing the bill. Borla seems to have taken quite a pathetic route to solve this problem. I suggest that SPO and Trey get on the phone and figure out what the hell this Borla fix all solution is all about and what they intend to do for the pissed off people such as myself that now have broken cars because of their product.
I purchased Wrapping for the Borlas tonight, but I'm not putting the headers back on until I figure out what the hell is going on.
My tech is more than willing to help me out with a OBDII scan tool, but I'm not sure that would help much. I'll try and go visit him in the next couple days and get the code pulled and all the extra info that he can extract from the freeze frame. I couldn;t get it last time because I had a misfire code first and the scan tool only saves the information from the first code in the ECU.
Kastle, Be sure and keep us posted on what yer car does. I'm getting my second replacement O2 sensor this week and I'm not putting the boras back on (if I do they will be wrapped) until someone finds something that resembles a solution.
I asked my tech to take a look at the O2 when he replaces it and to save it for me if at all possible so I can take some pictures and post um here, I am doing my best...
The tech and I looked at my O2 readings with the scan tool a week or so ago and (my CE light was on of course) and he said that they were in the specific parameters. I believe the reading was right around .875 or so, Not sure what the units are, just remember seeing that number on the OBDII.
Fred (my tech) told me that there are some minor differences between the ECU of the MY00 and MY01's that might make a difference. Anyone know anything about this? I'll try and ask him more the next time I talk to him.
Is this mysterious # that Borla is giving the second generation headers or maybe a third? Or just some bastard # he came up with to avoid dealing with a problem? What year Subes are having the ce problem?Here's what I have, follow suit where applicable
MY01 RS
Rallispec intake
Rallispec magnaflow 2.25 cat back exhaust with resonator
Borlas (duh)
NGK Plugs
*light comes on within 10 miles of each reset and stays on all the time
*I have run all octanes of fuel and still have the problem now running 87
*I have had my O2 replaced preceding any ce light problems
*My last tank of fuel got me a record low 14 MPG... yes folks... that's 14mpg. My boss gets better fuel economy with his MY00 Ford Excursion with the 7.3 Powerstroke.
*Thinking seriously about scrapping the 2.5 because of this and getting an Sti swap*
waltsacura@hotmail.com
AIM: Waltsacura


[This message has been edited by Waltsacura (edited January 04, 2001).]

Aaron,
Do you think the o2 could have had crap on it and finally you blew it off my running around for a while? I'll drive around for a few days and see if anything similar happens. Maybe the o2's are't bad but rather "plugged" from the freakin Borlas... but I doubt it's that easy.

posted twice... whoops

[This message has been edited by Waltsacura (edited January 04, 2001).]

Rob and Trey,
I think your both right.

Rob is right in that I don't think the ECU has anyway of detecting or determining that changes in VE have specifically occurred. However, Trey is correct about short and long term fuel trim.

I'm in no way an expert, far from it in fact, but here's my take on what Trey was getting at. When everything is working right, within the ideal, the baseline mapping should result in a certain A/F ratio. However, nothing is ever perfect and the A/F ratio will wander. I believe that's the reason for closed-loop A/F control, to better maintain a specific A/F ratio for emissions.

I'm not sure, because I've never had a Scan tool hooked and monitoring short and long term fuel trim while driving around, but I would think short term fuel trim are the consantly varying corrections that take place during closed-loop operation. I think it is long term fuel trim that we would associate with "learning". In other words, these corrections are made over longer periods of time and are stored. If the ECU is constantly making short term corrections in one direction, then something is amiss between the basic mapping and O2 sensor's A/F readings. Either something has occurred to throw off the baseline mapping, fuel delivery , or the O2 sensor is not provide accurate readings.

On a MAP based sysytem, things like changes in VE, bad MAP sensor, or bad Manifold air temperature sensor could throw off mass flow rate calculations and thus the wrong point on the fuel map would be used. Either too little or too much fuel will be delivered. The O2 sensor will detect this, and since this error will be of long duration it will be corrected for by long term fuel trim.

As injectors or fuel filter gets dirty, or other things occur to prevent the intended amount of fuel from being delivered, the O2 senor will again pick this up and corrections made. Mostly via long term fuel trim.

From this its easy to see the importance of the O2 sensor used to measure the A/F ratio. If it's in error, then long and short term corrections will be in error.

One of the things that I'm not totally sure of is which modes of operation does long term fuel trim apply.

Tony,
VE stands for Volumetric Efficiency. The Volumetric flow rate is the measure of the volume of air per unit time. When you multiply the volume flow rate by the density, you then get the mass flow rate. Its the density of the air that is changing with temperature and pressure in this case. And the temperature and pressure of the air is being taken into account.

[This message has been edited by Scottie (edited January 05, 2001).]

Walt -- that unit is volts. Good idea about removing the header for now, you're getting a bit too excited about this. (STi swap over this? C'mon.)

Whoever emailed Borla, their response TO ME indicates that the person answering was telling you about the second generation Borla header, *not* about a change to that very 2nd gen header to FIX the check engine light. Not a very attentive or informed customer service rep, in all likelihood.

Well, Dirty Underwear Gang has provided us with evidence of a fouled O2 sensor from running rich.

Now it's a question of the chicken before the egg. Was he running rich because the O2 sensor was providing bad input? Or was he running rich for some other reason, which then fouled the sensor and made things worse triggering the CE light under certain conditions?

From what I've read in several resources, if the tip of the O2 sensor is below its' minimum operating temperature, it will give a false lean reading. Thus the ECU would compensate and richen things up. This would eventually foul the O2 sensors with the black soot that Dirty Underwear Gang saw. What I'm wondering is, once fouled with this soot, would the sensor tend to give a false lean or false rich reading? The article that I provided at the top of this page was not clear on that. I'll have to do some more research.

The other possible scenerio that I can come up with is that the O2 sensor was working fine at first, but the changes in VE due to the Borla headers threw off the mass flow rate calculation enough that he ended up running rich. Now in closed-loop operation this would likely be quickly compensated for with short term corrections. However, in acceleration mode the O2 sensor is taken out of the loop and the stock mapping is relied upon. At most, long term fuel trim corrections might still be used, but it's likely insufficient time has passed for for long term corrections due to VE changes to have taken place yet. I mean, what is the first thing someone with new headers is going to do? Yep, they're going to go out and play. Meaning lots of time in acceleration mode. Hence, the O2 sensor could be getting fouled during this time. Then one thing leads to another. The fouled sensor starts providing bad info which is only worsened by cold temps.

Ok, enough rambling from me. My finger tips are getting sore. But this is one of the best threads I've seen in awhile. Lots of times multiple threads get started on the same topic, but for the most part everyone has been coming back here. Lots of people making good contributions.

One last thing. For those who know the codes that are being thrown, but don't what they stand for: http://www.ghg.net/dharrison/sae2012.htm
I'm pretty sure people have only mentioned P0 codes thus far.



[This message has been edited by Scottie (edited January 05, 2001).]

"If you have any problems with a BORLA product, involving either installation or performance, please call the company you bought it from immediately. BORLA Distributors will take all the necessary steps to insure you are satisfied".

paragraph 2, BORLA WARRANTY.

Okay here goes.
First off... My ce light is gone. I had the dealership install a new o2 today and the ce light has gone away and has stayed off for 50+ miles. The o2 has a little residue on it, prolly from the sulfur I guess, but Fred said it was nothing out of line. I'm going to drive around with the stock setup on for a while and then I'll re-install the Borlas once I take the time to wrap them.
My car was throwing a P0130 code which stands for O2 sensor lean Bank 1 Sensor 1. The first time I had the light pulled here were the stats from the freeze frame. 2.7% calc load. Long term fuel trim B1 (not sure if it is = or -, but I think it was minus)4.7%. Sort term fuel trim B1 37.5%. When I had the code pulled today from when I put the stock headers back on and was running around and had the light come on. The same P0130 code but the calc load was 23.5% Coolant temp was 109 degrees F. Short term fuel trim B1 37.5%. long term fuel trim b1 2.3%. It occured at 2075rpm traveling 47mph.
I hope this information helps those of you talking in the other language in the posts above. If there is anything else I can do please let me know.
I stickin with the "the Borlas broke my car" theory.
ColinL. Yes I do think it is extreme. but any excuse for me to get rid of an engine that's designed to have 165 hp and replace it with an entire powertrain assembly that is designed to have 280hp sounds like a good one. I'm not excited, I just want the car that I have sank over $25K into to run correctly and not throw CE lights... is that too much to ask?
When my light came on I had already had the Borlas on for over a week and I was also on a road trip with the cruise set at 70 mph, not really a lot of time spent at that moment in acceleration mode.
waltsacura@hotmail.com

3rd tank of gass and no light, all that is diferent is the batery...

Js

John,

Battery make, model #? You do also have an underdrive pulley, right?

Bob

[This message has been edited by Greborb (edited January 06, 2001).]

I got the optima yello top from sound domain.com $169.00

My lights still dim, but the ce-light is gone http://www.i-club.com/ubb-files/smile.gif so far

Js

I have sent the following to SPO Motorsports & Carr Subaru (guys I respect and like):

"Scott:

The borla warranty (2nd para) says:

"If you have any problems with a BORLA product, involving either installation or performance, please call the company you bought it from immediately. BORLA Distributors will take all the necessary steps to insure you are satisfied".

If you have taken any time recently to look at the Impreza Club Post on this problem, it will be clear that Borla has responded to no one. It should also be clear that the discussions/opinions are not merely mental masturbation, but very intelligent and extensive. If someone technically intelligent from Borla were to read it, my guess is they would immediately know how the headers were contributing to sensor and ecu anomalies and what the most pragmatic fix might be (perhaps things as simple as a high output battery, removal of fabrication residues, coating etc.).

Some time back, You indicated to me that you were working on it with Borla. As the impatience, on the part of everyone who has these headers, grows; my normal courtesy diminishes.

My take is that not a damn thing has been done. I've spoken to Bob Thompson about this as I'm about to have Carr put the stock headers back on. Bob indicated that you and he would try to contact Borla.

Scott, I am now a very very unhappy camper and Borla needs to step up to the plate here. I don't think anyone will buy these headers until they get an indication of what the remedies might be.

Bob Broberg"

do you guys know that the interstate extreme battery is actually an Optima battery? I put an interstate battery (800 CCA's red top) in steves car last week, (He doesn;t have the headers so it's not really relevant). I was thinking about getting one of these two batteries (red or yellow top) but then I learned about the reserve capacity of the battery. I don;t think our alternators are strong enough to charge them back up properly. Basicly I have come to the realization that 650CCA's is prolly the best battery for our cars. Does nayone else knw different? What is the output of our alternator? The yellow top is a deep cell battery right?
Still no CE light and I have the crappy stock battery still.

Well still no light with the borlas on, havent wrapped. Just the battery, i ordered a rebuilt bosch svx alternator 110 amps, hope it fits and keep my lights from dimming.

Js

Maybe the stonger battery is heating the element better?

Js

Sounds encouraging for those of us looking for an easy fix.

I've had the headers that I bought from AaronB on since Thursday and haven't gotten a CE light yet. He had them on for about 3 weeks in total.

kastle
<a href="http://www.azscooby.com" target="new">azscooby.com

I've been reading this thread with interest, as I am also considering the headers...

From what I have read so far, it sounds like it's not the borlas don't cause the light from the way they work, since a couple people stated they still got the CE light after they took them off.

They may however, damage the front 02 sensor in some way, perhaps from chemicals used in
construction of the headers...or it may be temperature related.

Now do I get to make everyone mad? I'm still not convinced that the CE light and the Borlas are related from reading these posts. I may have missed something, and there may be many more people with the problem than have posted here, which might convince me. However, the fact that there are a lot of people running the headers with no problems, and how all of your CE lights are kind of different makes me think that they may be cuased by something else.

From other posts on this board I remember thinking the 02 sensors were a little fragile to begin with, so you might get a bad one just as a coincidence, or as said earlier, damaged during install.

Don't want to offend anyone here, just stating what I think. Opinions?

Nebscoob,
You are right, the problem may not be specific with Borlas. I believe someone with MRT headers threw a CE light also. This problem seems to be specific to MY00's and MY01's during the cold weather. These same model years have been known to have O2 problems from that start (had mine replaced (MY00) once already right after I bought my car.). It does seem to be heat related. Actually now that I think of it, recent MY's are known to run rich after intake and exhaust mods. Rich=cooler exhaust temperatures, add cold weather and you get even cooler exhaust temperatures. It would be interesting to see if wrapping the headers, or using an S-AFC would alleviate this problem. Hopefully it's as simple as using the wrap. Whatever it's worth.
-Shawn

Shawn, who is the person w/ mrt exhaust that threw a CE? Just wondering
AO

double post - 'that sound homer makes'

[This message has been edited by m750 (edited January 08, 2001).]

m750,
It was Kwez, check out the link. http://www.i-club.com/ubb-files/Forum24/HTML/000698.html
He seems to be the only throwing the CE w/ the MRT's so far.

Talking to enough Sube techs leads me to believe that the problem between the MY00's and MY01's *MAY* be different. The MRT header problem was on a MY00 correct? I removed my Borlas, got a new O2 and BAM, I'm good to go with no CE light... car has A LOT more pull now too. I wrapped my Borlas and will be putting them on in the next few days... then we'll see whats up. Great info everyone... keep it comin...

Hey Walt...thanks for perservering. I spoke with Scott Orem (SPO) yesterday and he said he would try & talk with Borla. I strongly suggested they come on this post...talk to us about their opinions and remedies. Meantime, I'm intrigued with John's battery fix and what transpires as I look at my brilliant CE light.

Well still no light http://www.i-club.com/ubb-files/smile.gif I'm going to have the EGT and A/F installed on the 21st. And I'm going to try wrap the headers then also.

So at least we will know what is exactly going on...

Js

Well, I just installed a set yesterday. We'll see how I fare down here in Orlando. I have a MY01, Rallispec intake, Stromung cat-back..... I'm really fighting all odds.....

Did it get any louder with the Stromung cat-back? I understand the midpipe quiets things down...

The car was loud with just the muffler, then the mid pipe made it quieter, then after instaling the headers.... it's not loud at all.

Thanks. I have just the muffler so that's why I was wondering. I do NOT want to quiet my car down http://www.i-club.com/ubb-files/biggrin.gif

Over 100 miles with no ce light. I have the Rallispec 2.25 exhaust with the resonator. Adding the Borlas makes the car sound absolutely awesome. Great rumble down low and it absolutely opens up and screams at 5500rpm+. I still have the stock battery too...
John, do you still wanna wrap yer headers? I'll still give you hand if you want, come down and hang out in Philly for a day or so.
I wrapped mine with a single 1" x 50' roll, I could have used two and done a better job, but I think just one will do.
Anyone have an exhaust, uintake, headers and an s-afc? I can;t find any setting for a setup similar to mine. any suggestions?

*Back to top*
Don;t let it die folks. Has anyone done anything? I still have no light... it seems to be werking ok...
Paul;

Just reset ecu a few days ago. Am waiting for feedback from Walt & John before deciding on next steps....

[This message has been edited by Greborb (edited January 14, 2001).]

Well its back, after three tanks of gas, filled it up with texaco 92, and a mile later it's on ...

Now what?

Sunday; rallispec; guages; wrap ....

S--T, f--K, d-mn

Well its back, after three tanks of gas, filled it up with texaco 92, and a mile later it's on ...

Now what?

Sunday; rallispec; guages; wrap ....

S--T, f--K, d-mn

Geez John, I was hoping your battery/alternator mods would do it. http://www.i-club.com/ubb-files/confused.gif How cold is it in NJ?

Guess SPO Motorsport's effort to get Borla on this post fizzled. Really frustrating that the header maker doesn't seem to care.

rb

Guys,
Check out these links with info on O2 sensors. http://www.se-r.net/about/200sx/scc/july97/july.html
Scroll down to the part about headers etc.
and http://www.babcox.com/editorial/us/us110028.htm
Just some general info on O2's etc.
Judging from this information, I'm willing to bet that this issue is definately the temperature of the probe that is causing problems here and wrapping the headers should help, although time will tell. Whatever it's worth.
-Shawn

Had mine on for 8 mo with no CE light prob. but they did keep cracking. 3 times on the driver sid joint. so I cut them, welded in a flex pipe & put in a hi flow cat while I was at it. That caused a CE light. I just touch the bulb out, How will I ever pass inspection? http://albums.photopoint.com/j/View?u=1423409&a=10655363&p=36466961



[This message has been edited by Niloc (edited January 16, 2001).]

It appears that Niloc has the v.1 headers without the rerouted pipes and extra bracing. I haven't seen anyone with the v.2 headers cracking.

My check engine light comes on from time to time. I didn't take it to the dealer because they are giving me crap about my intake, so I just reset the ECU. I believe it has something to do with backpressure or the incoming air. I have a Weapon-R intake and a 5Zigen Cat-back. At first I thought it was the alarm, because, the first time the check engine light came on, I broke the mount where the siren sits on at Moroso. It scared the crap out of me at first, but now it comes on every now and then with regular driving. The next time it comes on I'm going to the dealer, I'll probably slip on the stock intake first though. Its not the headers, alone, its everything that we use to get more air in and out of the engine. Its really the damn OBD2 crapware thats screwing all of us from enjoying our mods. No trouble from the turbo guys, who aren't running stand alone ECU's?
Zee

I wrapped mine and still no ce light since my new o2 sensor. Stock battery still.
Rallispec intake, and cat back exhaust, it's flowing A LOT and still no light for the last 500 miles. I'm still holding onto my theory that the Borlas caused the o2 to go bad, wrapped the Borlas, ran them for a while with the blown o2 to burn out whatever was in the borlas. Borla hasn't said anything helpful... I will never buy anything from them again! If you have to have them, wrap them first

OK...mine just came back on after one tank full. What to do? Wrap I guess.

Damn Borla!

This shouldn't be a surprise. Cat's need to be very hot to work. By adding headers, you are adding a lot more surface area from which heat can disipate.

The cooler exhaust is probably also increasing carbon deposits in the system, which is what could be fouling your O2 sensor. I'd wrap the pipes - it's certainly not going to do any harm - and replace your O2 sensor. Replacing the sensor is a half-hour job and the new sensor should only be about $20. Then reset your ECU to clear the error codes and funky engine settings.

I'm not handy. What's it going to cost to have them wrapped and with what?

$20.00...if you can get o2 senors for Subaru's for $20.00 I'll buy a few cases of them. Are you nuts the o2 sensors for our cars sell for $150.00-$275.00 depending on the model.

gavin brings up a good point about the cat temperature. The unwrapped Borla headers are likely reducing the EGTs considerably as compared to stock. We've already talked some about how these lower temps might effect O2 sensor operation, but they may also have an adverse effect on the cats themselves.

There are couple of possible ways that a code for low catalytic converter efficiency might get thrown. One, the converter may not actually being doing it's job. And there could be several reasons for that like they're not hot enough. The other possibility is that the c