DTC P0171: 1/1 Fuel System Lean: Description

System is monitored with engine running in closed loop mode, ambient temperature more than 20°F (-7°C) and altitude less than 8000 feet. DTC will set when PCM determines fuel system has been too lean for 2 trips. Freeze frame will be stored and MIL will illuminate. Possible causes are: restricted fuel supply line, fuel pump inlet strainer plugged, defective fuel pump module, defective 1/1 HO2S, 1/1 HO2S signal circuit shorted to ground, Throttle Position (TP) sensor voltage more than .92 volt with throttle closed, defective TP sensor, defective Manifold Absolute Pressure (MAP) sensor, defective Engine Coolant Temperature (ECT) sensor, engine mechanical problem, defective fuel filter/pressure regulator or defective PCM.