Diagnostic Aids
WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
- Inspect for the following conditions:
- An exhaust leak can affect the HO2S accuracy.
- Inspect for a damaged front or rear oxygen sensor wiring harness.
- A TWC converter failure may be caused by any of the following conditions:
- Engine misfire can cause catalytic converter overheating.
- Inadequate secondary ignition voltage can cause incomplete combustion and catalytic converter overheating.
- Retarded ignition timing can cause performance concerns.
- Excessive engine oil or engine coolant consumption can damage the catalytic converter.
- Rich engine fueling can cause catalytic converter overheating.
- If a DTC P0420 or a DTC P0430 is intermittent, driving the vehicle under the conditions outlined in the Inspection/Maintenance (I/M) section can verify whether the fault is present.
- If a DTC P0420 or DTC P0430 cannot be duplicated, the information included in the Freeze Frame data can be useful in determining the vehicle operating conditions when the DTC was first set.