Catalytic Converter: Service and Repair

Catalytic Converter Replacement (LH6/LS2) (5.3L and 6.0L)

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 rear propeller shaft. Refer to Rear Propeller Shaft Replacement .
3. If equipped with four wheel drive (4WD), remove the front propeller shaft. Refer to Front Propeller Shaft Replacement .
4. Remove the transmission support. Refer to Transmission Support Replacement .
5. Remove the muffler to catalytic converter nuts (1).




6. Remove the front 2 muffler insulators (3 and 4) from the muffler hangers.
7. Pull back and separate the muffler (2) flange from the catalytic converter flange studs.
8. Reposition and secure the muffler end out of the way.
9. Remove and discard the old exhaust gasket.




10. Remove the catalytic converter to left exhaust manifold nuts (2).




11. Remove the catalytic converter to right exhaust manifold nuts (2).




12. Raise the transmission using the transmission jack for additional catalytic converter pipe clearance.
13. Tilt the catalytic converter in order to lower the left side pipe below the vehicle frame. Rotate the catalytic converter outlet pipe toward the left side of the vehicle to gain the necessary clearance for the right side pipe to clear the vehicle frame. Remove the catalytic converter (1) from the vehicle.
14. Remove and discard the catalytic converter to exhaust manifold seals.



Installation Procedure





1. Install the catalytic converter in reverse order of removal by starting with the catalytic converter outlet pipe angled toward the left side of the vehicle and positioning the right side pipe above the frame. Rotate the catalytic converter outlet pipe toward the rear of the vehicle and lift the left side pipe up above the frame.
2. Install a NEW exhaust seal to the right exhaust manifold.
3. Install a NEW exhaust seal onto the groove on the catalytic converter left side flange.
4. Install the catalytic converter (1) to the exhaust manifold studs.





Notice: Refer to Fastener Notice .

5. Install the catalytic converter to right exhaust manifold nuts (2).

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





6. Install the catalytic converter to left exhaust manifold nuts (2).

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





7. Insecure and position the muffler assembly.
8. Install a NEW exhaust gasket onto the catalytic converter studs.
9. Pull back and install the muffler (2) flange onto the catalytic converter flange studs.
10. Install the front 2 muffler insulators (3 and 4) to the muffler hangers.




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

Tighten the nuts to 45 N.m (33 lb ft).

12. Install the transmission support. Refer to Transmission Support Replacement .
13. If equipped with 4WD, install the front propeller shaft. Refer to Front Propeller Shaft Replacement .
14. Install the rear propeller shaft. Refer to Rear Propeller Shaft Replacement .
15. 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 .