Caution: In order to avoid being burned, do not service the exhaust system while it is still hot. Service the system when it is cool.

Caution: Always wear protective goggles and gloves when removing exhaust parts as falling rust and sharp edges from worn exhaust components could result in serious personal injury.

Important: Servicing of the mufflers, resonator or pipe requires the replacement of the exhaust system as a complete assembly.

1. Remove the oxygen sensor wiring harness heat shield. Refer to Oxygen Sensor Wiring Harness Heat Shield Replacement .
2. Remove the connector position assurance (CPA) retainer.
3. Disconnect the heated oxygen sensor (HO2S) electrical connector.



4. Remove the HO2S.



5. Remove the catalytic converter to the rear exhaust manifold pipe nuts.
6. Suitably support the exhaust system.



7. Remove the exhaust hanger to the rear suspension support bracket bolts.



8. Remove the rear exhaust hanger to hanger bracket nuts.



9. Remove the rear exhaust hanger bracket to the rear compartment side rail bolts.
10. With the aid of an assistant, lower the exhaust system.
11. Remove and discard the catalytic converter gasket.

Notice: When inspecting or replacing exhaust system components, make sure there is adequate clearance from all points on the underbody to prevent overheating of the floor pan and possible damage to the passenger compartment insulation and trim materials.

1. With the aid of an assistant, raise the exhaust system.
2. Install the rear exhaust hanger to hanger bracket studs.

Notice: Refer to Fastener Notice in the Preface section.

3. Install the rear exhaust hanger to hanger bracket nuts.

Tighten
Tighten the nuts to 30 N·m (22 lb ft).




4. Install a NEW catalytic converter gasket onto the studs.
5. Install the catalytic converter to the rear exhaust manifold pipe.
6. Install and snug the catalytic converter to the rear exhaust manifold pipe nuts.



7. Install the rear exhaust hanger bracket to the rear compartment side rail bolts.

Tighten
Tighten the bolts to 50 N·m (37 lb ft).




8. Install the exhaust hanger to the rear suspension support bracket bolts.

Tighten
Tighten the bolts to 30 N·m (22 lb ft).

9. Tighten the catalytic converter to the rear exhaust manifold pipe nuts previously installed.

Tighten
Tighten the nuts to 25 N·m (18 lb ft).




10. If reusing the old HO2S, coat the threads with anti-seize compound, GM P/N 12377953 or equivalent.
11. Install the HO2S.

Tighten
Tighten the sensor to 41 N·m (30 lb ft).




12. Connect the HO2S electrical connector.
13. Install the CPA retainer.
14. Install the oxygen sensor wiring harness heat shield. Refer to Oxygen Sensor Wiring Harness Heat Shield Replacement .