The Powertrain OBD System Check prompts you to complete some of the basic checks and to store the freeze frame and failure records data on the scan tool if applicable. This creates an electronic copy of the data captured when the malfunction occurred. The scan tool stores this data for later reference.

If any component DTCs are set, diagnose those DTCs first. A malfunction in a component can cause the converter to appear degraded or may have caused the malfunction.

This step includes checks for conditions that can cause the three-way catalytic converter to appear degraded. Repair any problems found before proceeding with this table.

If you need to replace the three-way catalytic converter, make sure that another condition is not present which would cause damage to the converter. Correct any possible causes of converter damage before replacing the catalytic converter in order to avoid damage to the replacement converter.

These conditions may include the following items:

Clearing the DTCs allows the catalyst test to be run up to 6 times this ignition cycle. Once the ignition switch is cycled, the test will run only once. Driving the vehicle heats the catalyst to a test temperature. The engine speed must be above idle for a predetermined amount of time before the PCM will allow the catalyst test to run. Once at idle, the PCM will allow the system to stabilize and then test the catalyst in 2 stages.

If you have found no malfunctions at this point and no additional DTCs were set, refer to Diagnostic Aids for additional checks and information.