p0171 and p0174
p0171 and p0174 Car is an 02 Trans Am. Engine was swapped out last year for a 6.0 L. While I was doing the swap, I installed the LS6 pcv upgrade and 799 heads, but no cam upgrade and the exhaust system is completely stock. Had a tune done and car ran fine. Only put on a few thousand miles and I put the car away for the winter. I added fuel preservative ( the new ethanol compatible style). Took the car out of storage last week and I now get p0171 and P0174 codes. I ran the fuel down to about 1/4 tank and added fresh Shell 93 octane. No help. I replace the fuel filter every year ( NAPA Gold), so filter cant be that old. Plan to replace it anyway, but I doubt that the problem is the filter. Some additional info. Sometimes the engine starts crisply and sometimes it starts and idles too low, tries to stall. It was doing that before it started to set the error codes, not sure if it is related. Otherwise, car runs fine, gets 23 mpg around town and seems to have plenty of power.
Launching!
Joined: Sep 2014
Posts: 259
Likes: 1
From: Peoria, AZ
Those codes P0171 and P0174 are - Fuel Trim System Lean both banks
I fixed mine with the P0174 code, it was either the fuel filter or the PCV valve, I just changed them both so not sure which one corrected it.
Maybe check your fuel pressure and check this out...........http://repairpal.com/OBD-II-Code-P0171-and-P0174
.
I fixed mine with the P0174 code, it was either the fuel filter or the PCV valve, I just changed them both so not sure which one corrected it.
Maybe check your fuel pressure and check this out...........http://repairpal.com/OBD-II-Code-P0171-and-P0174
.
Last edited by Stan1911; May 2, 2015 at 08:36 AM.
Those codes P0171 and P0174 are - Fuel Trim System Lean both banks
I fixed mine with the P0174 code, it was either the fuel filter or the PCV valve, I just changed them both so not sure which one corrected it.
Maybe check your fuel pressure and check this out...........http://repairpal.com/OBD-II-Code-P0171-and-P0174
.
I fixed mine with the P0174 code, it was either the fuel filter or the PCV valve, I just changed them both so not sure which one corrected it.
Maybe check your fuel pressure and check this out...........http://repairpal.com/OBD-II-Code-P0171-and-P0174
.
Staging Lane
Joined: Aug 2014
Posts: 50
Likes: 0
From: Detroit, MI
Is your PCV system drawing air BEHIND the MAF or in front of it? I'm not familiar with the LS6 PCV upgrade. If your drawing in air from in front of the MAF your going to be drawing in air not measured by the MAF, leaning out your fuel mixture. Just a thought.
Launching!
Joined: Sep 2014
Posts: 259
Likes: 1
From: Peoria, AZ
Forgot to mention, this started after I reinstalled the stock Y pipe. I had an SLP pipe installed, but it kept scraping on the ground so I went back to the stock pipe. I dont hear any leaks and I wonder if there was a leak, it would be after the O2 sensors so how could it affect the a/f ratio? I put in some 3M fuel injector cleaner and I have a new fuel filter and a can of MAF cleaner so that is the next step as well as checking FP. Why does this stuff always happen just as the car is due for state inspection???
The air is drawn from behind the MAF. The LS6 upgrade uses a new style valley cover and the PCV is in the valley cover. I made this change early last year and the car ran fine. This error just started last week. Plan to do some maintenance tomorrow ( fuel filter and clean the MAF).
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Verdad Gallardo Fixed ( I think)! Removed the MAF and it was about 80% plugged with mouse fur and pieces of leaves. Air filter was dirty, but not plugged. It had the center rows spread apart and that is where I believe the critter got in or at least the fur. Gave everything a good cleaning and replaced the air filter, drove around for over an hour, no check engine light. Not sure why a plugged MAF would indicate lean, I would have guessed rich. Not going to argue with success. I did check FP, it is a bit low, 52 psi static, 63 with the engine running. Couldnt get to the lift today so I will change the filter next week.Thanks for the replies.
Launching!
Joined: Sep 2014
Posts: 259
Likes: 1
From: Peoria, AZ
Fixed ( I think)! Removed the MAF and it was about 80% plugged with mouse fur and pieces of leaves. Air filter was dirty, but not plugged. It had the center rows spread apart and that is where I believe the critter got in or at least the fur. Gave everything a good cleaning and replaced the air filter, drove around for over an hour, no check engine light. Not sure why a plugged MAF would indicate lean, I would have guessed rich. Not going to argue with success. I did check FP, it is a bit low, 52 psi static, 63 with the engine running. Couldnt get to the lift today so I will change the filter next week.Thanks for the replies.
Glad you got it figured out.