1998 Ford F150 Trouble Code (PO171)

1998 FORD F-150
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JWG727
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Computer problem
1998 Ford F150 V8 Four Wheel Drive Automatic

I am getting a trouble code of PO171(System Adaptivefuel too lean) (Bank 1). What would be the probable cause?

Thanks
Jan 24, 2009 at 8:20 AM
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RASMATAZ
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P0171

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)
Jan 24, 2009 at 9:14 AM