Catalytic Converter: Service and Repair

Catalytic Converter Replacement (4.3L)

Removal Procedure





1. Remove the heated oxygen sensors (HO2S). Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 , Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 , Heated Oxygen Sensor Replacement - Bank 2 Sensor 1 , and Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 .
2. Remove the exhaust hanger bolts and hanger from the transmission.
3. Remove the catalytic converter to exhaust manifold nuts (1).




4. Remove the muffler to catalytic converter nuts (1).




5. Remove the catalytic converter (3) from the vehicle.
6. Remove and discard the exhaust manifold seals (1 and 2).



Installation Procedure





1. Install a NEW exhaust manifold seal (1) to the groove in the catalytic converter.
2. Install a NEW exhaust manifold seal (2) into the exhaust manifold.
3. Install the catalytic converter (3) to the vehicle.





Notice: Refer to Fastener Notice .

4. Install the muffler to catalytic converter nuts (1).

Tighten the nuts to 48 N.m (35 lb ft).





5. Install the catalytic converter to exhaust manifold nuts (1).

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

6. Install the exhaust hanger bolts and hanger to the transmission.

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

7. Install the HO2S. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 , Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 , Heated Oxygen Sensor Replacement - Bank 2 Sensor 1 , and Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 .