Mechanics

DTC

2000 Ford Expedition

Engine Performance problem
2000 Ford Expedition 5.4 - V8 - Four Wheel Drive Automatic 140,000 miles

Trouble codes:
P0171
P0174
P0301
P0442

Changed out injectors #1, 2, and 5
New Coils and plugs throughout

cannot remove fuel filter to change out-have tool but too little room

Did not find a vacuum leak using brake cleaner on vacuum lines while idling.
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James_wichman
November 27, 2009.



P0171/P0174

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)

Misfire at cyl no. 1 check the sparkplug/compression and injector on it

P0442-Evap leakage

Rasmataz
Nov 27, 2009.