GM Service Manual Online
For 1990-2009 cars only

Catalytic Converter Replacement Gasoline Engines

Removal Procedure

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


    Object Number: 1289510  Size: SH
  1. Disconnect the negative battery cable.
  2. Caution: 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

    Caution: Refer to Fastener Caution 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.

Catalytic Converter Replacement Diesel Engine

Removal Procedure

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


    Object Number: 1820482  Size: SH

    Warning: In order to avoid being burned, do not service the exhaust system while it is still hot. Service the system when it is cool.

    Caution: When inspecting or replacing exhaust system components, make sure there is adequate clearance from all points on the underbody to prevent overheating of the floor pan and possible damage to the passenger compartment insulation and trim materials.

  1. Disconnect the negative battery cable.
  2. Remove the exhaust manifold heat shield.

  3. Object Number: 1820483  Size: SH
  4. Remove the exhaust front pipe.
  5. Remove the pre-catalyst clamp.
  6. Remove the pre-catalyst bracket bolt from the engine block.
  7. Remove the pre-catalyst with the seal ring.

Installation Procedure


    Object Number: 1820483  Size: SH
  1. Install the pre-catalyst with the seal ring. If damaged, replace the new seal ring.
  2. Caution: Refer to Fastener Caution in the Preface section.

  3. Install the pre-catalyst clamp and the bracket bolt.
  4. Tighten
    Tighten the pre-catalyst bracket bolt to 40 N·m (29.5 lb ft).

  5. Install the exhaust front pipe. Refer to Front Pipe Replacement.

  6. Object Number: 1820482  Size: SH
  7. Install the exhaust manifold heat shield.
  8. Tighten
    Tighten the exhaust manifold heat shield bolt and nut to 20 N·m (14.8 lb ft).

  9. Connect the negative battery cable.