DTC P0171: 1/1 Fuel System Lean Or DTC P0174: 2/1 Fuel System Lean: Description

Fuel system lean condition is monitored with engine running in closed loop mode, ambient/battery temperature at more than 20°F (-6.7°C), and at altitude less than 8000 feet. DTC will set in Powertrain Control Module (PCM) memory when PCM senses fuel system is running too lean on 2 sequential trips. Possible causes for DTC to set are: defective Throttle Position (TP) sensor, binding throttle linkage, defective Engine Coolant Temperature (ECT) sensor, engine mechanical problem, fuel pressure out of specification or defective Manifold Absolute Pressure (MAP) sensor.