GM Service Manual Online
For 1990-2009 cars only

Catalytic Converter Replacement Gasoline Engine

Removal Procedure

    Caution: Refer to Battery Disconnect Caution in the Preface section.


    Object Number: 1289510  Size: SH
  1. Disconnect the negative battery cable.
  2. Notice: Handle the oxygen sensors carefully in order to prevent damage to the component. Keep the electrical connector and the exhaust inlet end free of contaminants. Do not use cleaning solvents on the sensor. Do not drop or mishandle the sensor.

  3. Disconnect the oxygen sensor electrical connector.
  4. Remove the exhaust manifold cover with the bolts.

  5. Object Number: 1289512  Size: SH

    Important: The nuts and the stud may unscrew as a unit because of the high temperature associated with the exhaust manifold, but they can be re-used as such.

  6. Remove the catalytic converter upper flange nuts.

  7. Object Number: 1289526  Size: SH
  8. Remove the exhaust front pipe mounting bracket bolt.
  9. Remove the nuts from the exhaust front pipe-to-catalytic converter flange.
  10. Remove the catalytic converter and the gasket.
  11. Clean the sealing surfaces on the exhaust front pipe flange and the exhaust manifold.
  12. Inspect the exhaust front pipe and the exhaust manifold for holes, damage, open seams or other deterioration which could permit exhaust fumes to seep into the passenger compartment.

Installation Procedure

    Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 1289526  Size: SH
  1. Install the catalytic converter and the gasket to the exhaust front pipe flange.
  2. Tighten

    • Tighten the exhaust front pipe-to-catalytic converter nuts to 40 N·m (30 lb ft).
    • Tighten the exhaust front pipe-to-cylinder block bolt to 50 N·m (37 lb ft).

    Object Number: 1289512  Size: SH
  3. Install the catalytic converter to exhaust manifold nuts and the gasket.
  4. Tighten
    Tighten the catalytic converter to exhaust manifold nuts to 40 N·m (30 lb ft).


    Object Number: 1289510  Size: SH
  5. Install the exhaust manifold cover bolts.
  6. Tighten
    Tighten the exhaust manifold cover bolts to 15 N·m (11 lb ft).

  7. Connect the oxygen sensor electrical connector.
  8. Connect the negative battery cable.