Removal Procedure

WARNING: This page is about a different car, the 2003 Buick Regal and 2003 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.

IMPORTANT: The three way catalytic converter is serviced by replacing the entire assembly. Always replace the gaskets at the front and rear flanges when servicing the three way catalytic converter. Never install the original gasket.

Raise and support the vehicle. Refer to LIFTING AND JACKING THE VEHICLE in General Information.
Disconnect the heated oxygen sensor (HO2S) electrical connector.
Remove the exhaust manifold pipe stud nuts.

Fig 1: Removing Exhaust Manifold Pipe Nuts
Courtesy of GENERAL MOTORS CORP.
Remove the exhaust manifold pipe gasket.
Support the exhaust system.
Remove the catalytic converter nuts.

Fig 2: Removing Catalytic Converter Nuts
Courtesy of GENERAL MOTORS CORP.
Remove the catalytic converter hangers.

Fig 3: Removing Catalytic Converter Hangers
Courtesy of GENERAL MOTORS CORP.
Remove the 3-way catalytic converter.
Remove the catalytic converter gasket.
Clean and inspect the exhaust manifold and the exhaust pipe gasket mating surfaces.
Remove the heated oxygen sensor (HO2S). Refer to HEATED OXYGEN SENSOR in Removal & Installation.