Catalytic Converter: Testing and Inspection

Diagnostic Procedures


Catalytic Converter, Checking

Observe all safety precautions: --> [ Safety Precautions ]

View clean working conditions: --> [ Clean Working Conditions ]

Prior to repair work, perform a preliminary check to verify the condition. Refer to --> [ Preliminary Check ] Preliminary Check.

Special tools, testers and auxiliary items required

• Generic scan tool

Test requirements

• Battery voltage at least 12.5 volts

• No leaks or damage to the exhaust system.

• Oxygen sensors OK

Test procedure

- Perform the function test in Diagnostic Mode 06. Refer to --> [ Diagnostic Mode 06 - Read Test Results for Specific Diagnostic Functions ] Diagnostic Modes 01 - 09.

If the specified values are exceeded:

- Check the exhaust system for leaks.

- Repair as necessary.

If no leaks are found in the exhaust system, no O2 sensor codes set and DTC P0420 is set:

- Replace the catalytic converter.

Final procedures

After repair work, the following work steps must be performed in the following sequence:

1. Check the DTC memory. Refer to --> [ Diagnostic Mode 03 - Read DTC Memory ] Diagnostic Modes 01 - 09.

2. If necessary, erase the DTC memory. Refer to --> [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Modes 01 - 09.

3. If the DTC memory was erased, generate readiness code. Refer to --> [ Readiness Code ] Monitors, Trips, Drive Cycles and Readiness Codes.