Catalytic Converter: Service and Repair

Catalytic Converter Replacement

Removal Procedure





1. Remove the muffler.
2. Remove the transmission support.
3. Disconnect the connector position assurance (CPA) retainers.
4. Disconnect the oxygen sensor electrical connectors (1, 2).





5. Remove the clip around the engine harness and oxygen sensor pigtail.
6. Disconnect the CPA retainer.
7. Disconnect the oxygen sensor electrical connector.
8. Remove the exhaust pipe hanger bracket bolts.
9. Remove the nuts attaching the insulator to the bracket.
10. Remove the insulator from the bracket.





11. Remove the right exhaust manifold pipe nuts.
12. Remove the left exhaust manifold pipe nuts.





13. Remove the left catalytic converter.





14. If equipped with a 6.0L engine, with regular production option (RPO) Y91, remove the left catalytic converter.





15. If equipped with a 6.0L engine, with RPO Y91, remove the right catalytic converter.





16. Remove the oxygen sensors if the catalytic converter(s) are to be replaced.

Installation Procedure





Notice: Refer to Fastener Notice in Service Precautions.

1. If the catalytic converter was replaced, perform the following:
1.1. Apply anti-seize compound GM P/N 12377953 or equivalent to the threads of the old oxygen sensors.
1.2. Install the oxygen sensors.
- Tighten the sensor to 42 Nm (31 ft. lbs.).





2. If equipped with a 6.0L engine, with RPO Y91, install a NEW exhaust manifold pipe seal to the right catalytic converter.
3. Install the right catalytic converter.





4. If equipped with a 6.0L engine, with RPO Y91 install a NEW exhaust seal to the left catalytic converter.
5. Install the catalytic converter.





6. Install a NEW exhaust seal to the catalytic converter.
7. Install the catalytic converter.





8. Install the left exhaust manifold pipe nuts.
9. Tighten the right exhaust manifold pipe nuts.
- Tighten the nuts to 50 Nm (39 ft. lbs.).





10. Install the insulator to the bracket.
11. Install the nuts attaching the insulator to the bracket.
- Tighten the nuts to 40 Nm (30 ft. lbs.).
12. Install the exhaust pipe hanger bracket bolts.
- Tighten the bolts to 17 Nm (13 ft. lbs.).
13. Connect the oxygen sensor electrical connector.
14. Connect the CPA retainer.
15. Install the clip around the engine harness and oxygen sensor pigtail.





16. Connect the oxygen sensor electrical connectors (1, 2).
17. Connect the CPA retainers.
18. Install the transmission support.
19. Install the muffler.