P0172 code and erratic cruise. Still can not find what is causing it!
Apr 20, 2009, 08:45 PM
#1
P0172 code and erratic cruise. Still can not find what is causing it!
Ok guys!
I am running into a situation where I just can not find a solution for it.
Snapshot:
After installing an FPRed, my car is recording code P0172 (System too rich) and experiencing a very bad cruising stalling/sputtering. Almost impossible to drive under 50% of throttle press. The AFRs are dropping to the lowest my WB will read 17.0 during the hesitation followed by a rich condition.
It seems that the car is like misfiring, like when one of the couplers in the IC piping is snapped. However, after leaving the cruising portion or in WOT the car is pushing very hard and no misfires/knocking is recorded.
Let me point that I did have a problem during the startup of the car after the turbo swap. The ECU was overheating coil pack for cyl 1&4 and misfiring pretty bad. After that, I got a new ECU and the car fired up w/o any problems.
The only thing that was different this time was that I connected a battery maintainer to the car which may have been the reason the ECU was fried.
Throubleshooting:
1. Boost leak test - None were found.
2. MAF swap - I got another Evo 9 MAF that is a known good one and still the same behavior.
3. Replaced spark plugs and gapped them accordingly. Denso IKH24.
4. IGN and Coil packs - I tried two different OEM IGN sets and my COP that was tested god on another Evo and still no go.
5. Fuel pressure is spot on even under load.
Final Thoughts:
The car was running fine with the green for a long time and only mechanical intervention was done with the exception mentioned above. It seems that if I clear up the trims the erratic cruise will ease up a bit and start to get worst as time passes and the long term kick in.
I have no idea what else it can be and I followed what most people will indicate for that code. I read some of the threads listed for that code and most of them pointed to a boost leak or faulty MAF which does not seem to be the case here.
Any idea of what may be causing this?
I am running into a situation where I just can not find a solution for it.
Snapshot:
After installing an FPRed, my car is recording code P0172 (System too rich) and experiencing a very bad cruising stalling/sputtering. Almost impossible to drive under 50% of throttle press. The AFRs are dropping to the lowest my WB will read 17.0 during the hesitation followed by a rich condition.
It seems that the car is like misfiring, like when one of the couplers in the IC piping is snapped. However, after leaving the cruising portion or in WOT the car is pushing very hard and no misfires/knocking is recorded.
Let me point that I did have a problem during the startup of the car after the turbo swap. The ECU was overheating coil pack for cyl 1&4 and misfiring pretty bad. After that, I got a new ECU and the car fired up w/o any problems.
The only thing that was different this time was that I connected a battery maintainer to the car which may have been the reason the ECU was fried.
Throubleshooting:
1. Boost leak test - None were found.
2. MAF swap - I got another Evo 9 MAF that is a known good one and still the same behavior.
3. Replaced spark plugs and gapped them accordingly. Denso IKH24.
4. IGN and Coil packs - I tried two different OEM IGN sets and my COP that was tested god on another Evo and still no go.
5. Fuel pressure is spot on even under load.
Final Thoughts:
The car was running fine with the green for a long time and only mechanical intervention was done with the exception mentioned above. It seems that if I clear up the trims the erratic cruise will ease up a bit and start to get worst as time passes and the long term kick in.
I have no idea what else it can be and I followed what most people will indicate for that code. I read some of the threads listed for that code and most of them pointed to a boost leak or faulty MAF which does not seem to be the case here.
Any idea of what may be causing this?
Apr 21, 2009, 03:12 PM
#3
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My car with my BBk is reading the exact same code. I had a friend read the code for me on Saturday. System to rich (bank 1) i believe 0172. I just bought some stuff to do a boost leak test myself. I feel your pain man. Its very hard to drive the car. I thought my clutch was going up as well.
I'm suppose to drop it off to CBRD sometime soon.
I'm suppose to drop it off to CBRD sometime soon.
Apr 21, 2009, 04:32 PM
#6
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Since you are saying the car runs just fine once you go WOT then it's something to do with closed loop.
How are your fuel trims? Does the front 02 voltage cycle? You might have damaged the front 02 sensor during the turbo install. I have seen this a handful of times.
If the front 02 is dead then it will default to dumping a ton of fuel.
How are your fuel trims? Does the front 02 voltage cycle? You might have damaged the front 02 sensor during the turbo install. I have seen this a handful of times.
If the front 02 is dead then it will default to dumping a ton of fuel.
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Apr 21, 2009, 05:44 PM
#8
I just performed another boost leak and a leak down test. All seem to be good. It feels that if a sensor got messed up or is acting up rather than a boost leak. My TB had a HUGE boost leak (way back when I had the green) at the TB shaft and was idling/cruising fine. No codes!
Idle term is -3 and cruise is at -12 due to all the stalling during cruise. If I reset them... Idle will stay the same and if I treat the gas pedal gently while accelerating trying to prevent the hesitation, I get -2 on the cruise trim.
The O2 follows what my WB is reading, if rich it will display .9xx and if lean, it will go to .5xx - .4xx.
I am inclined to think that a sensor is messed up based on the fried ECU. I will check with a good O2 to see if that helps.
Does the cam sensors may cause something like that? BTW... the JDM map is reading correctly.
Also, the fact that the car was running at its prime and all of the sudden starts to act up after a turbo swap is what is confusing me. Weird!
The cams have been in my car for almost a year and had no problems before. My car was running flawlessly just before the turbo swap and do not think the cams is the major offender on the car behavior. I am more concerned about the car driveability than the code itself.
Thanks to all for your inputs!
Since you are saying the car runs just fine once you go WOT then it's something to do with closed loop.
How are your fuel trims? Does the front 02 voltage cycle? You might have damaged the front 02 sensor during the turbo install. I have seen this a handful of times.
If the front 02 is dead then it will default to dumping a ton of fuel.
How are your fuel trims? Does the front 02 voltage cycle? You might have damaged the front 02 sensor during the turbo install. I have seen this a handful of times.
If the front 02 is dead then it will default to dumping a ton of fuel.
The O2 follows what my WB is reading, if rich it will display .9xx and if lean, it will go to .5xx - .4xx.
I am inclined to think that a sensor is messed up based on the fried ECU. I will check with a good O2 to see if that helps.
Does the cam sensors may cause something like that? BTW... the JDM map is reading correctly.
Also, the fact that the car was running at its prime and all of the sudden starts to act up after a turbo swap is what is confusing me. Weird!
Thanks to all for your inputs!
Apr 21, 2009, 07:31 PM
#9
Did you change any ROM information? Maybe added a patch or something?? I'm just guessing, but it seems very odd. 1st thought is to try to scale the injectors... then scale the MAF. On second thought I see you have the JDM map sensor, so it seems like your Ecuflash savvy... Would be nice to see what was botched with the first ECU...
Last edited by SWOLN; Apr 21, 2009 at 07:41 PM.
Apr 22, 2009, 06:59 AM
#11
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I know this is probably a dumb question, but do you vent to atmosphere? That will give you a bad hesitation, and most likely that code, since you are seeing less air than the MAS thinks is in there......
Apr 22, 2009, 07:20 AM
#13
Did you change any ROM information? Maybe added a patch or something?? I'm just guessing, but it seems very odd. 1st thought is to try to scale the injectors... then scale the MAF. On second thought I see you have the JDM map sensor, so it seems like your Ecuflash savvy... Would be nice to see what was botched with the first ECU...
Yes! Mine recirculates as well.
