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Old 01-03-2002, 01:18 PM   #1
tcs007
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Default My car is running really rich

Ever since I got my new exhaust put on 6 days ago, I have noticed a rather substantial build up of carbon on it. I know it has been cold, and so this atributes to this, but six days of driving looks like about a month of summer driving judging by the amount of build up.

2001 RS, Ganzflow Intake, Amsoil panel filter, Brullen Headers, custom mid, magnaflow muffler.

Is this to be expected? I know that the 2k's and 2k1's run rich, but this seems like a whole lot.

I do keep getting a ce light, and yes I did a reset, but I don't know of anyone that can scan it for me. I'm just assuming the rear o2 sensor isn't getting hot enough, possibly because I'm running to rich, because of the carbon build up.

Am I on the right track? Or am I talking out of my arse?

And then... How do I fix it? will a S-AFC work? Or am I going to need a tec-II?
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Old 01-03-2002, 01:36 PM   #2
Keiho
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Some people say fuel computers don't work on MY00-01 cars, and some do.

I for one have one on my MY00 and it seems to work as my exhaust isn't sooty at all.

I'd get the CE light checked out though, I thought the brullen headers aren't supposed to trigger CELs? And I'm pretty sure the Ganzflow doesn't trigger CELs.
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Old 01-03-2002, 01:54 PM   #3
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I KNOW its not the ganzflow. Its been on since I left the dealership!

I did recently pull a real boner, that may have been the last check engine light, though. I got gas, went to pay, and left the gas cap hanging in the holder of the gas cap cover. Took my a full day to discover that, and a ce light came up during that time.

I'll do another ecu reset today and see if anything comes up.

But I still need to fix this run rich problem.

I need to get my gauges installed so I can see a little clearer into what my car is doing.
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Old 01-03-2002, 05:06 PM   #4
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That gas cap thing WILL give you a CEL. I had mine on and I still got one. I just didn't click it three times (or whatever bogus crap the service guy said). So now I rip it on and let it click away.

I'm SERIOUSLY interested in the outcome of this thread, as my exhaust tip is all kinds of sooty.

Cobb CAI, SPT/Brospeed cat-back combo. If an S-AFC will take care of it, that may be next on my list of things to get.
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Old 01-03-2002, 11:20 PM   #5
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I got Brullen headers since Nov 22 '01. No CELs. Other mods include PRM intake, street cams, UR Pulley, Brullen 2.25 exhaust.
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Old 01-04-2002, 12:03 AM   #6
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Almost every 2000+ runs rich with mods, usually not enough to cause problems. Disabling long term fuel trim with the IWTU Torque Chip II (or proECM powerchip) often fixes this.

It might be possible you are getting a CE light for "catalyst efficiency below threshhold" although I am told even the brullen un-coated headers don't trigger this light. Are yours jet hot coated or not?

Some people have been able to lean out the 2000+ with an SAFC by about 15% for best results (up to 5 hp max gain), but most of the time when you lean it out the 2000 ECU then gives you a loping idle and a CE light for "low manifold ABS/Barometric pressure circuit". Seems some ECU's tolerate subtracting fuel better than others. Mine wouldn't let me subtract more than 10% fuel before the CE light, and anything over (-)5% at 1,000 rpm would set it off.

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Old 01-04-2002, 12:18 AM   #7
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How long has it been since the last ECU reset. Cause just after a reset, all subies are known to run excessively rich. Yes, a rich fuel system will cause a cat efficiency CE light cause the cat never comes up to temperature.

Do you have a place to do some spirited runs safely?

If you do, please engage in some entertaining fun, hopefully you can force the ECU to compensate.

The job of the front O2 sensor is actually to detect "Rich or Lean" conditions so that the ECU can alter the fuel map to compensate. If you can get your hands on an OBDII reader, have them check the signal from the front O2 sensor.

It should fluctuate like crazy. If it doesn't, that maybe the problem.

The rear O2 sensor signal should be fairly stable.

Another potential cause for the rich condition is a leak at the manifold gaskets, this would interfere with the front O2 reading and may cause too much fuel to be injected.

So to recap, 2 things to check

1) Gasket leaks in front manifold get the car up on a hoist and feel for exhaust leaks while car is on idling fast, you'll feel the leak, and see some telltale carbon marks. A sure fire way to spot the leak is to actually remove the headers and inspect the gasket, you'll definately see the blowby marks if there was a leak.

2) Get to an OBDII reader and check the signal from the front O2 sensor while the car is running, it shuld be fluctuating quite fast.

Keep us informed.

Thanks

PS, do you notice any power increase with the headers though?
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Old 01-04-2002, 12:32 AM   #8
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http://www.i-club.com/forums/showthr...hreadid=115926

go to this thread

MAP sensor, Throttle position sensor, Temp etc= base fuel map depending on engine load, throttle position etc

O2 sensor, fine tunes in CLOSED LOOP. WOT is open loop. @ WOT, the more flow mods you have the richer you'll run.

Rich = colder combustion, cylinder and exhaust temps= low efficiency on catalyst CEL crap.

Fixes:
proper fuel management; ie. tech II (the right way) SAFC (not as good way)
Wrap headers to retain more heat (bandage fix, still runs rich, but no CEL)
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Old 01-04-2002, 01:21 AM   #9
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Ok I read all of the posts here and in the other thread, and the only thing I know for sure is that my head hurts, and I have a black tail-pipe.

Oh, and my car has small backfires about 50% of the time when I upshift, and sometimes just driving down the road it'll let loose with a bang under my feet.

But I don't get the CEL. So what's going on here?
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Old 01-04-2002, 02:33 AM   #10
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same stuff.
You're still rich.
I have the same backfires.
Only you are one of the lucky guys that either maintains enough heat in your exhaust or your ecu isn't as picky. Believe it or not, no two ECU's are identical; just like no two cars are identical. You don't have headers so you aren't losing as much heat as the rest of us.

"spirited runs" only help temporarily. And only for CEL's. Car will still run rich. WOT fuel maps don't "learn" the same as the closed loop operations because they don't use the O2 sensor. I could be wrong, but the only thing that I think "learns" @ WOT is timing curves.

WOT= Wide Open Throttle... just in case someone didn't know.
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Old 01-04-2002, 03:12 AM   #11
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Default My car runs rich..

I wish my bank account is "rich" but that's another thing.

I've got a PDM intake and a Stromung Dual-tip exhaust. The exhaust tips always become dirty after a day or so of driving. I just polish it up with a clean cloth and some polishing compound and I'm back to bling-bling stainless steel tips.

As for the CE light - follow what the others have suggested. I don't have anything to add about that.

LaterZ!
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Old 01-04-2002, 10:44 AM   #12
tcs007
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I know our cars run rich, but I feel its running WAY too rich. 6 days of driving and I have a thick coat of carbon on my exhaust tip. That seems awfully excessive to me, especially since I've had the car since new, and she now has over 18,000 miles on her.
I've never noticed this much carbon build up before.
I'm sure part of it has to do with it being much colder suddenly, and probably the freeing up of the airflow, but it still seems excessive amounts of carbon have built up. Less than 500 miles on the new exhaust, and it looks like I have never cleaned the exhaust in 20,000 miles. It's that thick!

Larry- No, my pipes aren't ceramic coated, and the check engine light isn't what really is bothering me. It's the excessive soot on my exhaust. I was waiting for the final results on the TC-2 chip before I bought one, but it seems all I ever find on that thread is someone griping about "dyno numbers", and "g-tech results can be faked" etc., etc. If you say it may help, I may have to go ahead and get one from you and see if it helps.
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Old 01-04-2002, 01:53 PM   #13
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The only real way to tell if our cars are truly running rich or not is through a 3rd party air-fuel ratio monitor and to tune for that. Then again, if you want things to run "perfect," you'll have to run a TEC-2 or some other standalone ECU to tune it.

LaterZ!
Darren!!
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Old 01-04-2002, 02:01 PM   #14
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Quote:
Originally posted by tcs007
I know our cars run rich, but I feel its running WAY too rich. 6 days of driving and I have a thick coat of carbon on my exhaust tip. That seems awfully excessive to me, especially since I've had the car since new, and she now has over 18,000 miles on her.
I've never noticed this much carbon build up before.
I'm sure part of it has to do with it being much colder suddenly, and probably the freeing up of the airflow, but it still seems excessive amounts of carbon have built up. Less than 500 miles on the new exhaust, and it looks like I have never cleaned the exhaust in 20,000 miles. It's that thick!
Give the ECU soem time to correct the fuel but the stock WOT map approaches a 9:1 a/f ratio the closer it comes to redline....therefor you are REALLY just wasting fuel. an S-AFC will fit the WOT maps but the car will learn around it in closed loop operation.

Jeremy
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Old 01-04-2002, 03:00 PM   #15
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Ok see my day-to-day driving is what many people would consider 'spirited' driving. When it's screaming through the revs, it's adding more and more fuel, I get that, but it sounds like it isn't adding as much air as fuel. ??
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Old 01-04-2002, 10:07 PM   #16
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Exclamation Some people actually

set a "negative" value for their fuel trim to lean out the air-fuel ratio to get more power. I guess it works both ways! Richen it up if the ECU is "lean" by nature, or lean it out if the ECU is programmed to be on the "rich" side.

LaterZ!
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Old 01-05-2002, 06:05 AM   #17
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Default Re: Some people actually

Quote:
Originally posted by Penphoe
set a "negative" value for their fuel trim to lean out the air-fuel ratio to get more power. I guess it works both ways! Richen it up if the ECU is "lean" by nature, or lean it out if the ECU is programmed to be on the "rich" side.

LaterZ!
Darren!!
exactly my man....well to a point there are certain spots in the rev band that are excessively lean and spots that are excessively rich...for NA to get the most power tune for a 15.3-15.5:1 a/f ratio...running lean builds more power...running rich kills power...needless to say why there is NO reason to run 9:1 a/f ratio @ redline. i'd like to shoot the guy that desinged that map.

jeremy
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Old 01-05-2002, 12:00 PM   #18
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So, I got another check engine light after doing the ecu reset. So I've now got the car up on stands and am inspecting everything. I pulled the rear o2 sensor, and it is black from soot, and I mean BLACK.
What's the correct way to clean an o2 sensor? Is there a correct way?
I've got no exhaust leaks, so that's out of the way. I think my whole problem boils down to running rich. Maybe like Jeremy said, I just need to run with a check engine light for a couple of weeks, and then do a "fast" ecu reset (basically reset the ce light) and see if that takes care of it. If it doesn't, then I'll try something else. Maybe a S-AFC, maybe Larry's TC2, maybe both, maybe neither.
When's the next hooters meet? I need someone with an OBD-II scanner to tell me what this is. It might not even be o2 sensor related.
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Old 01-05-2002, 01:35 PM   #19
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the rear O2 is covered in soot?? oh man you must just be dumping fuel, have you pulled any of the plugs?? If you have hte MIL on it's prolly going to be a fuel trim code...soemthings wrong...do you have a catalyst in place??

Jeremy
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Old 01-06-2002, 06:07 PM   #20
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I've got the high flow cat that brullen sent me.

Midwayman- I got your pm. Thanks for the offer. When are you available? I can do it anywhere, anytime after 6pm for this week.
Now Jeremy's got me all worked up about me pouring fuel away. I'm still getting pretty good gas mileage though.
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Old 01-07-2002, 04:55 AM   #21
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okay well covered to me might be a different covered to you...there will be soot on the O2 just shouldn't be caked on there...what kinda mileage you getting?? how many miles on the car??

Jeremy

p.s.: Don't always listen to me cause i do it for a living so some words translate differently to me.
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Old 01-07-2002, 08:56 AM   #22
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About 18,600 miles. the o2 sensor had a layer of soot on the outside of it. I wiped it off with a paper towel (hoping I didn't break it), and re-installed it.
I'm getting about 300+ miles a tankful, same as I was before the exhaust.
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Old 01-07-2002, 03:13 PM   #23
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you are fine...if it had barbon build up that's a sign of VERY rich...you are normal....man 300 miles a tank?? hopefully that's highway and you aren't a total gas sippa!!! hehee j/p.

jeremy
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Old 01-08-2002, 04:05 AM   #24
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300 miles a tank is just under 19mpg if you run it dry. I usually go a bit farther on a tank.
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Old 01-08-2002, 08:22 AM   #25
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You might not have as heavy a foot as I do
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