Catalytic Converter: Testing and Inspection

THREE-WAY CATALYTIC CONVERTER (TWC) INSPECTION

CAUTION: Perform the following procedures if only DTC P0420 is detected.

NOTE: Make sure that no HO2S DTCs have been detected. If detected, this inspection is not applicable for TWC inspection.

1. Connect the WDS or equivalent to the DLC-2.
2. Verify that the HO2S DTCs are not detected using the WDS or equivalent.
- If an HO2S DTC is detected, perform the appropriate DTC inspection procedure. (See DTC TABLE) Diagnostic Trouble Code Descriptions

3. Clear the DTC form the PCM memory using the WDS or equivalent.
4. Start the engine and warm it up to normal operating temperature.
5. Verify that the engine compression is within the specification.
- If the compression pressure is not within the specification, repair or replace any malfunctioning part.

6. Drive the vehicle at Drive Mode 3. (See OBD-II DRIVE MODE) OBD-II Drive Mode
7. Access Test ID 10:21:80 using the "Diagnostic Monitoring Test Result" function.
8. Verify that the test result is within the specification as indicated on the WDS or equivalent.
- If not as specified, replace the catalytic converter.