Possible Causes
Possible causes are:
- Using leaded fuel.
- Oil contamination.
- Engine misfire.
- Damaged HO2S.
- Malfunctioning ECT sensor.
- Downstream HO2S wires improperly connected.
- Fuel pressure too high.
- Damaged exhaust system pipe.
- Damaged exhaust manifold.
- Damaged muffler/tailpipe assembly.
- Damaged catalytic converter.
- Retarded spark timing.