These are what can cause a P0171
HO2S and sensor connection.
Fuel injector and/or fuel injector circuitry.
Powertrain Control Module (PCM).
Electrical circuits (HO2S, HO2S GND, INJ 1-8, VPWR and SIG RTN).
To prevent replacement of good components, be aware the following non-EEC areas may be cause of driveability concerns:
Faulty evaporative emission system.
EGR and/or PCV system.
Air intake system.
Engine oil contamination.
Exhaust system leaks or restriction.
Engine cooling system.
A scan tool would help for diagnostics.
Saturday, September 22nd, 2012 AT 8:59 AM