Diagnostic Aids
WARNING: This page is about a different car, the 2002 Pontiac Sunfire, 2002 Pontiac Grand Am, 2002 Oldsmobile Alero, and 2002 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.
Catalyst test may abort due to a change in engine load. Do not change engine load, that is, do not reset A/C, coolant fan, or heater motor while a catalyst test is in progress.
Certain conditions may cause a catalytic converter to degrade. These conditions may include the following conditions:
- Engine misfire.
- High engine oil or high coolant consumption.
- Retarded spark timing.
- Weak spark.
- Lean fuel system.