P2178 - System Too Rich At Off Idle Right Bank
- Faulty front heated oxygen sensor
- Ignition misfiring
- Faulty fuel injectors
- Incorrect fuel pressure
- Faulty Mass Air Flow (MAF) sensor
- Incorrect Positive Crankcase Ventilation (PCV) hose connection
With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the theoretical mixture ratio based on the mixture ratio feedback signal from the heated oxygen sensors 1. The Engine Control Module (ECM) calculates the necessary compensation to correct the offset between the actual and the theoretical ratios.
In case the amount of the compensation value is extremely small (The actual mixture ratio is too rich.), the ECM judges the condition as the fuel injection system malfunction and light up the MIL (2 trip detection logic).
Any information is appreciated. Thanks