Catalytic Converter Replacement 3.4L

Replace the entire converter assembly in order to properly service the three way catalytic converter.

1. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
2. Remove the exhaust manifold pipe nuts from the exhaust manifold pipe studs.



3. Remove the catalytic converter nuts from the exhaust pipe.
4. Remove the three-way catalytic converter.
5. Clean the three-way catalytic converter mating surfaces.

Notice: To prevent internal damage to the flexible coupling of the catalytic converter assembly, the converter must be supported. The vertical movement at the rear of the catalytic converter assembly must not exceed 6 degrees up or down.

1. Install a new catalytic converter gasket.
2. Install a new exhaust manifold pipe gasket.
3. Position and support the new three-way catalytic converter under the vehicle.
4. Install the exhaust pipe to the three-way catalytic converter with the catalytic converter nuts. Do no tighten the nuts.




Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

5. Install the exhaust manifold pipe nuts to the exhaust manifold pipe studs.

Tighten

•	Tighten the exhaust manifold pipe nuts to the exhaust manifold pipe stud to 32 N·m (26 lb ft).

•	Tighten the catalytic converter nuts to the 34 N·m (25 lb ft).

6. Lower the vehicle.
7. Inspect the exhaust system for leaks.

Catalytic Converter Replacement 3.8L

The three way catalytic converter is serviced by replacing the entire assembly. Always replace the gasket at the front flange when servicing the three way catalytic converter assembly. Never reinstall the original gasket.

1. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
2. Disconnect the heated oxygen sensor (HO2S) electrical connector.
3. Remove the exhaust manifold pipe stud nuts.



4. Remove the catalytic converter bolts.
5. Remove the three way catalytic converter.
6. Remove the exhaust manifold pipe gasket at the catalytic converter front flange.



7. Remove the heated oxygen sensor (HO2S). Refer to Heated Oxygen Sensor 1 Replacement in Engine Controls - 3.8L.

1. Install the heated oxygen sensor (HO2S). Refer to Heated Oxygen Sensor 1 Replacement in Engine Controls - 3.8L.
2. Install a new exhaust manifold pipe gasket to the exhaust manifold pipe studs.

Notice: Refer to Catalytic Converter Movement Notice in the Preface section.




3. Install and support the three way catalytic converter.
4. Install the catalytic converter bolts.



5. Install the exhaust manifold pipe stud nuts.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

Tighten

•	Tighten the exhaust manifold pipe stud nuts to 32 N·m (24 lb ft).

•	Tighten the catalytic converter bolts to 45 N·m (33 lb ft).

6. Connect the heated oxygen sensor (HO2S) electrical connector.
7. Lower the vehicle.
8. Inspect the exhaust system for leaks.