Dtc p0171

[robdup2005]

Need help has a 97 PA with code P0171 I have replace both O2 sensors,MAF,Idle control,Check for vacuum leak, and also replace fuild filter but code still show up every morning i start the car i let it warm up and every time the code pop on, I would value any input i can get right now.

[1967 BB]

I had the same DTC 0171 with my 1997 Ultra. Replaced MAF sensor fuel filter and did the other tests in the GM manual. Turns out the aftermarket MAF sensor I installed was defective. I replaced it and the light has not been on again for 3 months.

[DeltaP]

A code P0171 may mean that one or more of the following has happened:

The MAF (Mass Air Flow) Sensor is dirty or faulty
Note: The use of "oiled" air filters may cause the MAF to become dirty if the filter is over-oiled. There is also an issue with some vehicleswhere the MAF sensors leak the silicone potting material used to protect the circuitry.
There could be a vacuum leak downstream of the MAF sensor
Possible cracked vacuum or PCV line/connection
Faulty or stuck open PCV valve
Failed or faulty oxygen sensor (bank 1, sensor 1)
Sticking/plugged or failed fuel injector
Low fuel pressure (possible plugged/dirty fuel filter!)
Exhaust leak between engine and first oxygen sensor

[robdup2005]

check everything on your list I haven't check for exhaust leak yet will take to muffle shop have it check thank alot for the infor,

[happyreefer]

I found a leak on my 94 PAU between the EGR and the intake. i have a flexible pipe that had small cracks at the flange underneath the mounting hardware for this pipe. i had cracks on both ends.

be advised that this part number GM#24504158 is discontinued. i ended up using JB weld to repair these cracks. seems to be working fine. no more P0171 code.

if you happen to remove this to check for the leak i am talking about. the flexible pipe is flexible, but be careful as you can cause these cracks i talk about by just removing it. the pipe inserts slightly into each location (one side more than the other) and care must be taken not to damage it.

Gary

[robdup2005]

Thanks Gary for your reply I had a hold in my flex pipe got one off on ebay , but the code still popping up. Don"t know what to try next I"m goinh to change spark plug next see do thet help. Thank again

[Tech II]

OK, you are at the point where you need a scan tool on this vehicle, especially reading data when the MAF is disconnected.......and also while spraying the engine, to check O2 data.....