Removal Procedure

WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
If equipped, unclip the oxygen sensor connection from the floor reinforcement.

Fig 1: Oxygen Sensor Connection At Floor Reinforcement (4.3L, 4.8L, and 5.3L Engines)
Courtesy of GENERAL MOTORS CORP.
Disconnect the oxygen sensor electrical connector.

Fig 2: View Of O2 Sensor Harness Routing And Harness Mounting Brackets

GM664828

Courtesy of GENERAL MOTORS CORP.

Remove the oxygen sensor clips from the frame.
Disconnect the connector position assurance (CPA) retainers.
Disconnect the oxygen sensor electrical connectors.

Fig 3: View Of O2 Sensor Harness Routing

GM664951

Courtesy of GENERAL MOTORS CORP.

Unclip the oxygen sensors electrical connectors from the following:
- Hose clip
- Transmission crossmember
Disconnect the CPA retainers.
Disconnect the oxygen sensor electrical connectors (1, 2).

Fig 4: View Of Left Exhaust Manifold Pipe & Nuts

GM858550

Courtesy of GENERAL MOTORS CORP.

Remove the left exhaust manifold pipe nuts.

Fig 5: View Of Right Exhaust Pipe Nuts

GM858553

Courtesy of GENERAL MOTORS CORP.

Remove the right exhaust manifold pipe nuts.

Fig 6: Exhaust Muffler Nuts (4.3L, 4.8L, and 5.3L Engines)

GM664840

Courtesy of GENERAL MOTORS CORP.

Remove the exhaust muffler nuts.
Remove the catalytic converter.

Fig 7: View Of Oxygen Sensors

GM664954

Courtesy of GENERAL MOTORS CORP.

If necessary, remove the oxygen sensors.