Catalytic Converter Replacement

Catalytic Converter Replacement (V8)

Removal Procedure
Warning: Refer to Exhaust Service Warning (Exhaust Service Warning).

Warning: Refer to Protective Goggles and Glove Warning (Protective Goggles and Glove Warning).





1. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle (Service and Repair).
2. Disconnect the heated oxygen sensor (HO2S) electrical connectors from the main harness connectors.




3. Remove the nuts (1) from the catalytic converter pipe to the exhaust manifolds.




4. Remove the nuts from the catalytic converter pipe to the muffler.
5. Remove the catalytic converter from the vehicle.
6. Remove and discard the exhaust manifold seals.
7. If replacing the catalytic converter pipe, remove the oxygen sensors as necessary. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 (Heated Oxygen Sensor Replacement - Bank 1 Sensor 1).

Installation Procedure

Note: A special anti-seize compound is used on the heated oxygen sensor (HO2S) threads. The compound consists of liquid graphite and glass beads. The graphite tends to burn away, but the glass beads remain, making the sensor easier to remove. New, or service replacement sensors already have the compound applied to the threads. If the sensor is removed from an engine and if for any reason the sensors are to be reinstalled, the threads must have anti-seize compound applied before the reinstallation.

1. If reusing the old HO2S sensors, coat the threads with ant-seize compound GM P/N 5613695.




2. Install the oxygen sensors to the catalytic converter. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 (Heated Oxygen Sensor Replacement - Bank 1 Sensor 1).
3. Install NEW seals to the exhaust manifolds.
4. Position the catalytic converter to the exhaust manifolds and the muffler.
5. Install the catalytic converter to muffler nuts, but do not completely tighten.





Caution: Refer to Fastener Caution (Fastener Caution).

6. Install the catalytic converter nuts to the exhaust manifold studs and tighten to 65 Nm(48 lb ft).




7. Tighten the catalytic converter to muffler nuts (1) to 48 Nm (35 lb ft).




8. Connect the HO2S electrical connections to the main harness connectors.

Caution: Refer to Exhaust System Inspection Caution (Exhaust System Inspection Caution).

9. Lower the vehicle and inspect for exhaust leaks.