Diagnostic Aids
WARNING: This page is about a different car, the 2006 Pontiac Montana SV6, 2006 Chevrolet Uplander, and 2006 Buick Terraza. However, it is still accessible from the selected car via links, so may be relevant.
- These conditions may cause a catalytic converter to degrade. Inspect for the following conditions:
- An engine misfire
- High engine oil or high coolant consumption
- Retarded spark timing
- A weak or poor spark
- A lean fuel mixture
- A rich fuel mixture
- A damaged oxygen sensor or wiring harness
- The catalyst test may abort if the vehicle falls outside the conditions for running the DTC.
- The catalyst test may abort due to a change in engine load such as the A/C or engine cooling fan cycling.
- If 18 tests have been attempted and the DTC has not run or passed during this key cycle, turn the key to OFF for 30 seconds. Perform the conditions for running a second time.
- If an intermittent condition cannot be duplicated, the information included in the Freeze Frame/Failure Records can be useful in determining the vehicle operating conditions when the DTC was set.
- The catalyst may have been temporarily contaminated with a chemical from a fuel additive, fuel contamination or any of the above conditions.
- If the condition is determined to be intermittent, refer to Testing for Intermittent Conditions and Poor Connections .
CAUTION:
Refer to Road Test Caution
.
IMPORTANT:
A new catalyst may fail this test due to out-gassing of the internal matting. If this occurs, operate the vehicle at highway speeds for approximately one hour and retest.