2003 Pontiac Grand Prix PO171 code

JOHNNYVLTD1

MEMBER
2003 PONTIAC GRAND PRIX

Computer problem
2003 Pontiac Grand Prix 6 cyl Front Wheel Drive Automatic

had intake manifold leak radiator fluid leaking outside of motor not into oil had repaired with tune up plugs wires fuel filter pcv etc. Car running great but service engine light came on day later code po171 running to lean bank one what should I do besides go back to mechanic have small code reader checked it cleared it light came back on

2 Replies

RASMATAZ

MECHANIC
75,992 POSTS

P0171 lean condition:

A lean fuel condition can be caused by:

* Low fuel pressure due to a weak pump or leaky fuel pressure regulator. (Use a fuel pressure gauge to check fuel pressure at idle)

* Dirty fuel injectors. (Try cleaning the injectors)

* Vacuum leaks at the intake manifold, vacuum hose connections or throttle body. (Use a vacuum gauge to check for low intake vacuum)

* Leaky EGR valve. (Check operation of EGR valve)

* Leaky PCV Valve or hose. (Check valve and hose connections)

* Dirty or defective Mass Airflow Sensor (MAF). (Try cleaning the MAF sensor wires or filament with aerosol electronics cleaner. Do NOT use anything else to clean the sensor, and do not touch the sensor wires)