Exhaust Seal Replacement for Pontiac Grand Prix 2004

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.

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

3. Remove the exhaust manifold nuts (2) from the exhaust manifold pipe studs.

Important: Support the exhaust system where hangers are removed.

4. Remove the catalytic converter exhaust hangers.
5. Reposition the exhaust system.
6. Remove the exhaust manifold pipe gasket (1).

1. Install the exhaust manifold pipe gasket (1).
2. Install the exhaust system to the original position
3. Install the catalytic converter exhaust hangers.
4. Remove the support from the exhaust system .

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 stud nuts (2).

Tighten
Tighten the nuts to 35 N·m (26 lb ft).

6. Connect the HO2S electrical connector.
7. Inspect the exhaust system for leaks and underbody contact.
8. Lower the vehicle.