This Preliminary Information communication provides information to the technician of a possible service engine soon light. Technician will find a diagnostic trouble code P0171 with no engine performance concerns. This could be caused by unmetered air entering the engine due to an intake leak or air filter concern. If Service Information diagnostics doesn?t isolate the cause of this concern inspect the air intake system for rolled connections cracks or loose clamps between the mass air flow sensor and the throttle body, repair as necessary. Inspect the screen that is on the inlet side of the air outlet duct for damage. If the long term trim is consistently above 10 percent temporarily remove the air filter and reset the fuel trims. Evaluate the long term fuel trim if it remains at 0 percent with the air filter removed replace the air filter with the latest part number listed in the parts catalog.
