System Rich, L-Idle Adap at Lean Limit

NAME OF CODE
System Rich. L-Idle Adap at Lean Limit

SET CONDITION
Engine running rich; Powertrain Control Module (PCM) trying to adapt fuel/air mixture lean.

THEORY OF OPERATION
This trouble code can be caused by several things not related to PCM electronics. Idle adaptive memory is designed to aid in fuel/air control. Its function is to adapt the fuel/air mixture to correct for fuel pressure differences and other mechanical changes such as engine wear and mechanical malfunctions. The fuel control system goes to open loop mode when the oxygen sensor has indicated a continuous rich mixture of exhaust gas.

POSSIBLE CAUSES
- Catalyst
- EGR system
- Fuel pressure
- Injectors
- MAP sensor
- O2 sensor
- Coolant temp sensor
- Evaporative emission system
- Wiring harness/connectors