GM Service Manual Online
For 1990-2009 cars only

Catalytic Converter Replacement - Left Side 3.6L Engine

Removal Procedure

  1. Disconnect the battery ground cable from the battery. Refer to Battery Negative Cable Disconnection and Connection .
  2. Remove the engine dress cover. Refer to Engine Cover Replacement .
  3. Notice: Refer to Heated Oxygen and Oxygen Sensor Notice in the Preface section.


    Object Number: 1949881  Size: SH
  4. Remove the left pre-catalytic converter heated oxygen sensor (HO2S) wiring loom from the engine wiring loom retaining clip (1).
  5. Disconnect the left pre-catalytic converter heated oxygen sensor (HO2S) wiring connector (2) from the main wiring harness.
  6. Caution: Refer to Exhaust Service Caution in the Preface section.

    Caution: Refer to Protective Goggles and Glove Caution in the Preface section.


    Object Number: 1949688  Size: SH

    Important: The left catalytic converter to exhaust manifold retaining nuts (2) are single use parts. They must be discarded after removal.

  7. Remove the left catalytic converter to exhaust manifold retaining nuts (2).
  8. Discard the nuts.

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

  9. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle .
  10. Pull down and back on the left catalytic converter (3) to disconnect from the exhaust manifold (1).

  11. Object Number: 1947042  Size: SH

    Important: The intermediate exhaust assembly to left catalytic converter retaining nuts (3) are single use parts. They must be discarded after removal.

  12. Remove the intermediate exhaust assembly to left catalytic converter retaining nuts (3).
  13. Discard the nuts.

  14. Disconnect the intermediate exhaust assembly (2) from the left catalytic converter (1).

  15. Object Number: 1949679  Size: SH
  16. Remove the left catalytic converter (1) from the vehicle.
  17. Remove the left pre-catalytic converter HO2S. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 .

Installation Procedure

    Notice: Refer to Exhaust Service Caution in the Preface section.

  1. Install the left pre-catalytic converter HO2S to the left catalytic converter. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 .

  2. Object Number: 1949679  Size: SH
  3. Install the left catalytic converter (1) to the vehicle.

  4. Object Number: 1949688  Size: SH

    Important: Make sure that a NEW sealing ring is fitted prior to installation. Failure to comply may cause the exhaust system to perform poorly.

  5. Lift the left catalytic converter (3) up and forward to connect to the exhaust manifold (1).
  6. Lower the vehicle.
  7. Important: Do not fully tighten the left catalytic converter to exhaust manifold retaining nuts (2) at this stage.

  8. Install the left catalytic converter to exhaust manifold retaining nuts (2).
  9. Do not fully tighten at this stage.

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

  10. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle .

  11. Object Number: 1947042  Size: SH
  12. Align the intermediate exhaust assembly (2) to the left catalytic converter (1).
  13. Notice: Refer to Fastener Notice in the Preface section.

  14. Tighten the intermediate exhaust assembly to left catalytic converter retaining nuts (3).
  15. Tighten
    Tighten the nuts to 40 N·m (30 lb ft).

  16. Lower the vehicle.

  17. Object Number: 1949718  Size: SH
  18. Tighten the left catalytic converter to exhaust manifold retaining nuts (1).
  19. Tighten
    Tighten the nuts to 45 N·m (33 lb ft).

  20. Make sure that the exhaust system is clear of all other components and chassis. If the exhaust system is not clear of all the other components loosen all retaining nuts and re-align. Refer to Exhaust System Alignment .
  21. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle .

  22. Object Number: 1949881  Size: SH
  23. Connect the left pre-catalytic converter heated oxygen sensor (HO2S) wiring connector (2) to the main wiring harness.
  24. Install the left pre-catalytic converter heated oxygen sensor (HO2S) wiring loom to the engine wiring loom retaining clip (1).
  25. Lower the vehicle.
  26. Install the engine dress cover. Refer to Engine Cover Replacement .
  27. Connect the battery ground cable to the battery. Refer to Battery Negative Cable Disconnection and Connection .
  28. If re-programming is required. Refer to Control Module References .
  29. Perform diagnostic system check using diagnostic scan tool, clear all relative DTCs and inspect the system for correct operation.

Catalytic Converter Replacement - Left Side 6.0L Engine

Removal Procedure

  1. Disconnect the battery ground cable from the battery. Refer to Battery Negative Cable Disconnection and Connection .
  2. Caution: Refer to Exhaust Service Caution in the Preface section.

    Caution: Refer to Protective Goggles and Glove Caution in the Preface section.


    Object Number: 1949706  Size: SH

    Important: The left catalytic converter to exhaust manifold retaining nuts (1) are single use parts. They must be discarded after removal.

  3. Remove the left catalytic converter to exhaust manifold retaining nuts (1).
  4. Discard the nuts.

  5. Disconnect the left catalytic converter (2) from the exhaust manifold (3).
  6. Caution: Refer to Vehicle Lifting Caution in the Preface section.

  7. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle .
  8. Notice: Refer to Heated Oxygen and Oxygen Sensor Notice in the Preface section.


    Object Number: 1950735  Size: SH
  9. Disconnect the left pre-catalytic converter heated oxygen sensor (HO2S) electrical connector (1).

  10. Object Number: 1947042  Size: SH

    Important: The intermediate exhaust assembly to left catalytic converter retaining nuts (3) are single use parts. They must be discarded after removal.

  11. Remove the intermediate exhaust assembly to left catalytic converter retaining nuts (3).
  12. Discard the nuts.

  13. Disconnect the intermediate exhaust assembly (2) from the left catalytic converter (1).

  14. Object Number: 1949679  Size: SH
  15. Remove the left catalytic converter (1) from the vehicle.
  16. Remove the left pre-catalytic converter HO2S. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 .

Installation Procedure

  1. Install the left pre-catalytic converter HO2S to the left catalytic converter. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 .
  2. Caution: Refer to Exhaust Service Caution in the Preface section.


    Object Number: 1949679  Size: SH

    Important: Make sure that a new sealing ring is fitted prior to installation. Failure to comply may cause the exhaust system to perform poorly.

  3. Install the left catalytic converter (1) to the vehicle.

  4. Object Number: 1947042  Size: SH
  5. Align the intermediate exhaust assembly (2) to the left catalytic converter (1) by pushing back and down on the intermediate exhaust assembly (2).

  6. Object Number: 1949706  Size: SH
  7. Push up and forward on the left catalytic converter (2) to connect to the exhaust manifold (3).
  8. Lower the vehicle.
  9. Install the left catalytic converter to exhaust manifold retaining nuts (1).
  10. Tighten the left catalytic converter to exhaust manifold retaining nuts (1).
  11. Tighten
    Tighten the nuts to 45 N·m (33 lb ft).

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

  12. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle .

  13. Object Number: 1947042  Size: SH
  14. Install the intermediate exhaust assembly to left catalytic converter retaining nuts (3).
  15. Notice: Refer to Fastener Notice in the Preface section.

  16. Tighten the intermediate exhaust assembly to left catalytic converter retaining nuts (3).
  17. Tighten
    Tighten the nuts to 40 N·m (30 lb ft).


    Object Number: 1950735  Size: SH
  18. Connect the left pre-catalytic converter HO2S electrical connector (1).
  19. Make sure that the exhaust system is clear of all other components and chassis. If the exhaust system is not clear of all the other components loosen all retaining nuts and re-align. Refer to Exhaust System Alignment .
  20. Lower the vehicle to the ground.
  21. Connect the battery ground cable to the battery. Refer to Battery Negative Cable Disconnection and Connection .
  22. If re-programming is required. Refer to Control Module References .
  23. Perform diagnostic system check using diagnostic scan tool, clear all relative DTCs and inspect the system for correct operation.