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Old 03-31-2003, 01:47 PM   #1
Kingtut R-S
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Default Hesitation

Hi there:

I have a 2001 RS, 26,000 miles on it. My car has this strange hesitationfrom 2,000 to 4,000rpms. Its like a misfire, or and electrical interference of some sort. The car idles ok, around 600 RPM´s. My first impression was sparkplugs, So i went and changed them with NGK´s BKR6E-11 The car stayed the same. So i went and changed fuel filter, cleaned and recharged my KN air filter, and added some VP C-12 Racing fuel to clean the fuel system. Also reseted the computer. Went for a 45 minute sprinted drive and coming back the CEL light went on again. So i finally decided to perform the grounding mode. 10 feet of 10 gauge wire, connectors and some nice location points and the grounding mode was done. Then, the hesitation comes backs after installing it. I feel that its worsethan before...

Any ideas?
Mods- Ganzflow with -KN and catless 2.25 exhaust with WRX rear section.

Any help would be greatly appreciated.
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Old 03-31-2003, 02:15 PM   #2
Teamugi
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Did you get the CEL code pulled? That might be the first step.
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Old 03-31-2003, 09:56 PM   #3
jaycee
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With the grounding mod, it might be helpful to do an ECU reset.
See if that helps.

I had hesitation too, around 3,000 rpm+ . After the grounding mod, and ECU reset, my car is smoother and the bogging/jolting from shifting is totally gone. But I used 8 guage wires. Don't know if it makes a difference over 10 guage.
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Old 04-01-2003, 03:54 AM   #4
joefocker20
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You probably have the CEL from your lack of Cats.. The hesitation is the cam profile.. SPG mod isnt going to do anything..
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Old 04-03-2003, 12:13 PM   #5
Kingtut R-S
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joefocker20:

what can it be done to fix it???

Replace with a high flow cat?

Thanks for the replies.

BTW: the code was the cat ineficiency code....
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Old 04-03-2003, 10:16 PM   #6
Kingtut R-S
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T T T. anybody else have any ideas??
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Old 04-03-2003, 11:02 PM   #7
syncros
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Default not a suggestion but...

I have exactly the same set up as you: NGK sparkplugs, ganzflow w/ k&n panel filter, 2.25 midpipe w/ wrx muffler, grounding mod. Only difference is I've never experienced any kind of hesitation., nor any CEL's. The mods only made the car smoother and more powerful throuhgout the rev range. My point is given that we have the same setup and I have no problems, your issue is something that should be correctable. Perhaps an ECU reflash?
The Gidster

edit: I just re-read and saw you are catless. That is a difference - I've got no silencer due to the custom midpipe, but I do still have the stock cat.

Last edited by syncros; 04-04-2003 at 04:04 PM.
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Old 04-05-2003, 06:08 PM   #8
SubaruImpreza_power
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Question wrong thread..

sorry posted in wrong thread..
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Old 04-06-2003, 08:03 AM   #9
joefocker20
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Well, you can either replace it with a high flow cat, or buy a MIL eliminator.
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Old 04-06-2003, 09:43 AM   #10
ChicksDigWagons
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Definately sounds like an O2 sensor, but the hessitation shouldn't be caused by a bad rear o2 reading. Perhaps your front O2 sensor is bad, mine is acting the same way from a bad front 02. Feels like there is no power then BAM it kicks in like a shot of nitrous...sucks. Get the code pulled so you know for sure.
-Brad
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Old 04-06-2003, 05:51 PM   #11
watcher in the sky
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I have noticed that when you crank your car.. and let it completely warm up.. the hesitation is basically gone.. also.. the car runs much much smoother, shifting smoother as well. Simple solution really
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Old 04-06-2003, 06:02 PM   #12
matt8416
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Default hesitation

there is updated ecu reprograming for this problem, your car is wihtin 3-36 (3 years,36000 miles)bring it to dealer for fix in some cases it has to be removed and sent to SOA (subaru of america)for reprogram
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Old 05-18-2003, 11:35 AM   #13
wavecruzer79
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Default the anwser

Quote:
Originally posted by Kingtut R-S
T T T. anybody else have any ideas??
Check your Knock sensor it senses for detination erors vibration in your cylinders it sits to the left of your throttle body and when it goes bad it can retard your timing and make a check light come on i hear it is really common it should be arround 36$ at a dealer
( only buy subby stuff at the dealership like that)
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Old 05-18-2003, 12:18 PM   #14
Cujo31
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It's your Front Oxygen Sensor.


I'll lay $100000000 on a P130 code.
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Old 05-19-2003, 02:43 AM   #15
scotty305
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go into a little more detail: is it a sharp, abrupt 'stutter', or does the car smoothly lose power at certain speeds?

If it's a stutter, check your plug wires. Open hood at nighttime when it's dark, turn on your engine, look for sparks.

Does your car throw a Check Engine Light? (sorry I read very quickly, might've missed if you said already) If it throws a blinking CEL, go to the dealer ASAP, you could be damaging things by driving w/ a blinking check engine light.

-s-
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Old 05-19-2003, 05:47 PM   #16
mysubaruimp
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i have same problem, no power from around 1200-2200rpm, then at exacly 2200, BAM off like the wind. i dont have a CEL though. mods are:apexi s-afc2(maps at 0%, so should have no effect), borla catback, borla header, intake, lightweight pulley, think thats all that would effect it
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Old 03-03-2007, 01:45 PM   #17
Adam F
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Old thread, I know. But I'm having similar problems with my mom's bone stock 02' Outback 2.5. Random bad hesitation and poor fuel mileage. I did a tuneup (plugs, fuel filter, air filter, etc) and even went as far as changing the ignition coil. No dice, still hesitates. Never got any codes up until today. CEL came on. Mom went to Autozone and they told her P130 O2 sensor. I looked at the DTC codes and there was a P0130 but no P130. But did some searches here and found P130 is apparently the front 02 sensor. I'm guessing this is right after the manifold?

So is it safe to say the sensor is bad, or should I do some testing? How do I test it? Where is the best place to get a replacement? Brand/price?

sorry for the thread hijack!
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Old 03-03-2007, 02:33 PM   #18
LewBob
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Quote:
Originally Posted by Adam F View Post
Old thread, I know. But I'm having similar problems with my mom's bone stock 02' Outback 2.5. Random bad hesitation and poor fuel mileage. I did a tuneup (plugs, fuel filter, air filter, etc) and even went as far as changing the ignition coil. No dice, still hesitates. Never got any codes up until today. CEL came on. Mom went to Autozone and they told her P130 O2 sensor. I looked at the DTC codes and there was a P0130 but no P130. But did some searches here and found P130 is apparently the front 02 sensor. I'm guessing this is right after the manifold?

So is it safe to say the sensor is bad, or should I do some testing? How do I test it? Where is the best place to get a replacement? Brand/price?

sorry for the thread hijack!
Check the grounding mod thread. I was having similar problems with my 2002 Legacy. After the grounding mod I feel like I have a new car. LewBob
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Old 03-03-2007, 06:56 PM   #19
Adam F
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Quote:
Originally Posted by LewBob View Post
Check the grounding mod thread. I was having similar problems with my 2002 Legacy. After the grounding mod I feel like I have a new car. LewBob

That says hesitation at 3500-4500rpms...hers hesitates right from idle.
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Old 03-03-2007, 07:26 PM   #20
LewBob
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Mine was hesitating at various RPM's. I stalled it a number of times coming from a stop. Pretty embarrassing for a guy who has driven a stick all his life. I changed spark plugs and plug wires, then remembered the grounding thread. Immediate relief with just a few wires run.(I did it in spare time so it took a few days to get all the wires run). It is worth trying. LewBob
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Old 03-03-2007, 11:43 PM   #21
Jhemy
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I had a very similar problem with my 2.5 RS. Turned out mine was caused by the tip of my cylinder 2 sparkplug snapping off causing a mis-fire though haha. I replaced the sparkplugs all around and did an ECU reset just in case and my car has been fine since this happened about 3 weeks ago.
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