GM Service Manual Online
For 1990-2009 cars only

When removing the catalytic converters (1), it is necessary to disconnect the wiring harness connectors from the pre-catalytic oxygen sensor.

Service Precautions

    • Keep the oxygen sensor free of contaminates. Do not use any solvents to clean the sensor.
    • Do not attempt to repair any part of the sensor including the wiring and connector. Replace the sensor if any damage is evident.
    • When the exhaust system is cold the oxygen sensor may be difficult to remove. Excessive force may damage the threads in the exhaust assembly.
    • If reusing the old oxygen sensor apply an anti-seize compound to the thread. New oxygen sensors come with the compound already applied.

Removal Procedure

    Caution: Refer to Vehicle Lifting Caution in the Preface section.

    Caution: Refer to Safety Glasses Caution in the Preface section.

  1. Disconnect the battery ground cable from the battery. Refer to Battery Negative Cable Disconnection and Connection .
  2. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle .

  3. Object Number: 1950735  Size: SH
  4. Disconnect the wiring harness connector (1) to the oxygen sensor wiring harness.
  5. Remove the left catalytic converter from the vehicle. Refer to Catalytic Converter Replacement - Left Side .
  6. Loosen and remove the oxygen sensor (2). Take care not to damage the oxygen sensor.

Installation Procedure


    Object Number: 1950735  Size: SH

    Important: If using the old oxygen sensor (2) coat the threads with an anti-seize compound.

  1. Install the oxygen sensor (2) to the left catalytic converter.
  2. Tighten
    Tighten the oxygen sensor to 40 N·m (30 lb ft).

  3. Install the left catalytic converter to the vehicle. Refer to Catalytic Converter Replacement - Left Side .

  4. Object Number: 1950735  Size: SH
  5. Connect the wiring harness connector (1) to oxygen sensor wiring harness.
  6. Lower the vehicle.
  7. Connect the battery ground cable to the battery. Refer to Battery Negative Cable Disconnection and Connection .
  8. If re-programming is required. Refer to Control Module References .
  9. Check for codes using a suitable scanner,