P0171 System Too Lean (Bank 1)
#1
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P0171 System Too Lean (Bank 1)
Hey guys,
This code just popped up yesterday and after scanning the car, I am confused and unsure why it exists. Here is what the FSM says:
0115
Diagnostic Trouble Code 0115 indicates a problem with the fuel management system on the right cylinder bank. The right bank is also called the rear bank. It is cylinders 1,3,5.
The Front Heated Oxygen Sensor for the right bank sent signals to the Engine Control Module indicating an excessively lean fuel mixture. The ECM attempted to correct this problem by directing the fuel injectors to supply more gasoline. Further signals from the Oxygen Sensor indicate that the attempt to correct the lean mixture condition was unsuccessful, and the fuel mixture continues to be too lean.
Possible causes include ...
- Intake air leaks
- Defective Front Heated Oxygen Sensor
- Fuel injectors
- Exhaust gas leaks
- Incorrect fuel pressure
- Lack of fuel
- Faulty Mass Air Flow Sensor
I have completed an 00vi swap, but it was done 7 months ago and the only problem I have had since then was a misfire (1 coilpack fixed it) and the cold start issue (fixed by drilling and tapping the IACV hose fitting on the mainfold).
-Both Front O2 sensors were replaced when the 00vi was installed (~5000 miles ago).
- I just cleaned the complete intake assembly to the throttle body about a month ago and made sure there were no leaks.
- I have a minor exhaust leak, but it is nothing major and I have been driving with it since April when I installed the catback.
-My MAF is fine because the car does not buck or hesitate.
I am lost here, and really don't know where to start. Any input is appreciated.
Thanks guys,
Matt
This code just popped up yesterday and after scanning the car, I am confused and unsure why it exists. Here is what the FSM says:
0115
Diagnostic Trouble Code 0115 indicates a problem with the fuel management system on the right cylinder bank. The right bank is also called the rear bank. It is cylinders 1,3,5.
The Front Heated Oxygen Sensor for the right bank sent signals to the Engine Control Module indicating an excessively lean fuel mixture. The ECM attempted to correct this problem by directing the fuel injectors to supply more gasoline. Further signals from the Oxygen Sensor indicate that the attempt to correct the lean mixture condition was unsuccessful, and the fuel mixture continues to be too lean.
Possible causes include ...
- Intake air leaks
- Defective Front Heated Oxygen Sensor
- Fuel injectors
- Exhaust gas leaks
- Incorrect fuel pressure
- Lack of fuel
- Faulty Mass Air Flow Sensor
I have completed an 00vi swap, but it was done 7 months ago and the only problem I have had since then was a misfire (1 coilpack fixed it) and the cold start issue (fixed by drilling and tapping the IACV hose fitting on the mainfold).
-Both Front O2 sensors were replaced when the 00vi was installed (~5000 miles ago).
- I just cleaned the complete intake assembly to the throttle body about a month ago and made sure there were no leaks.
- I have a minor exhaust leak, but it is nothing major and I have been driving with it since April when I installed the catback.
-My MAF is fine because the car does not buck or hesitate.
I am lost here, and really don't know where to start. Any input is appreciated.
Thanks guys,
Matt
#4
I had this two weeks ago (for a long time)...it was a ghost code (got it with a code reader).
I ended up cleaning my MAF because I also had a fluctuating idle...the cleaning of the MAF with electronic parts cleaner from CRC fixed the issue.
It's probably the same issue for you.
It might also be a vac. leak as stated...my MPG didn't suffer, and it's only improved a little since...so don't worry too much about this. It's not a horrible problem.
I ended up cleaning my MAF because I also had a fluctuating idle...the cleaning of the MAF with electronic parts cleaner from CRC fixed the issue.
It's probably the same issue for you.
It might also be a vac. leak as stated...my MPG didn't suffer, and it's only improved a little since...so don't worry too much about this. It's not a horrible problem.
#5
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Join Date: Jan 2007
Location: Wrentham,MA/Smithfield,RI
Posts: 4,517
Thanks for the help guys. I really don't think I have a vacuum leak, only because the car has been running the best it has since I did the 00vi swap. I'll check my MAF, it only takes a few minutes to clean it too.
When I go into work tomorrow I'll clear the codes and see if it comes back.
Thanks for the help.
When I go into work tomorrow I'll clear the codes and see if it comes back.
Thanks for the help.
#7
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Join Date: Oct 2005
Location: Middleboro/Carver, Ma
Posts: 4,572
^yes yes and yes.
Hey got your message earlier matt, don't clear the code just yet, or if you do it at your work in the scanner go into "view freeze frame data" and check the RPM that it happened at. I wouldn't doubt a vacuum leak, either the temp one from the other day during that fitting install (Don't know when your cel came on) or your egr guide tube. If it's the guide tube we will have to set some time up BEFORE tuning that biotch. Tuesday wednsday or thursday of next week should work for me if I have to pull the '00vi, already got the gaskets for it, and the stuff for the rear hub as well.
Big thing you didn't mention, and no one picked up on......
I'm pretty sure you know how to do this, but if you need clarification shoot me a call:
NT to HT switchover point= make sure it's 30%, and make sure you have no NT corrections )I might be off on my abbr. but narrow or low throttle vs wide or high throttle)
Hey got your message earlier matt, don't clear the code just yet, or if you do it at your work in the scanner go into "view freeze frame data" and check the RPM that it happened at. I wouldn't doubt a vacuum leak, either the temp one from the other day during that fitting install (Don't know when your cel came on) or your egr guide tube. If it's the guide tube we will have to set some time up BEFORE tuning that biotch. Tuesday wednsday or thursday of next week should work for me if I have to pull the '00vi, already got the gaskets for it, and the stuff for the rear hub as well.
Big thing you didn't mention, and no one picked up on......
I'm pretty sure you know how to do this, but if you need clarification shoot me a call:
NT to HT switchover point= make sure it's 30%, and make sure you have no NT corrections )I might be off on my abbr. but narrow or low throttle vs wide or high throttle)
Last edited by KRRZ350; 08-06-2008 at 06:22 PM.
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