GM Service Manual Online
For 1990-2009 cars only

Removal Procedure - Up to 31 May 2007

  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.

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

  3. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle .
  4. Support the exhaust system using a suitable jack.
  5. Remove the rear exhaust muffler assemblies. Refer to Exhaust Muffler Replacement - Left Side and Exhaust Muffler Replacement - Right Side .
  6. Notice: Refer to Heated Oxygen and Oxygen Sensor Notice in the Preface section.


    Object Number: 1949882  Size: SH
  7. Disconnect the left post-catalytic converter heated oxygen sensor (HO2S) electrical connector (1).

  8. Object Number: 1949877  Size: SH
  9. Disconnect the right post-catalytic converter 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: 1947044  Size: SH

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

  15. Remove the intermediate exhaust assembly to right catalytic converter retaining nuts (3).
  16. Discard the nuts.

  17. Disconnect the intermediate exhaust assembly (2) from the right catalytic converter (1).

  18. Object Number: 1947045  Size: SH
  19. Remove the intermediate exhaust assembly to rear muffler retaining bolts (3).

  20. Object Number: 1947040  Size: SH
  21. Detach the intermediate exhaust assembly (2) by removing the front insulator hangers (1) if fitted.

  22. Object Number: 1947047  Size: SH
  23. Detach the intermediate exhaust assembly (2) by removing the centre insulator hanger bracket to differential retaining bolt (1).
  24. Carefully lower the intermediate exhaust assembly from the vehicle.
  25. Remove the left post-catalytic converter HO2S. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 or Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 .
  26. Remove the right post-catalytic converter HO2S. Refer to Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 or Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 .

Installation Procedure - Up to 31 May 2007

  1. Clean all threads and flange faces of the intermediate exhaust system.
  2. Always check the condition of the catalytic converter to intermediate pipe flange gaskets and replace as necessary.
  3. Install the left post-catalytic converter HO2S to the intermediate exhaust system. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 or Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 .
  4. Install the right post-catalytic converter HO2S to the intermediate exhaust system. Refer to Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 or Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 .
  5. Notice: Refer to Exhaust System Inspection Notice in the Preface section.

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

  6. Position the intermediate exhaust assembly to the vehicle using a suitable jack.

  7. Object Number: 1947047  Size: SH
  8. Attach the intermediate exhaust assembly (2) by installing the centre insulator hanger bracket to differential retaining bolt (1).

  9. Object Number: 1947040  Size: SH
  10. Attach the intermediate exhaust assembly (2) by installing the front insulator hangers (1) if fitted.
  11. Tighten the intermediate exhaust assembly to rear muffler retaining bolts.
  12. Tighten
    Tighten the bolts to 45 N·m (33 lb ft).


    Object Number: 1947044  Size: SH
  13. Align the intermediate exhaust assembly (2) to the right catalytic converter (1).
  14. Notice: Refer to Fastener Notice in the Preface section.

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


    Object Number: 1947042  Size: SH
  17. Align the intermediate exhaust assembly (2) to the left catalytic converter (1).
  18. Tighten the intermediate exhaust assembly to left catalytic converter retaining nuts (3).
  19. Tighten
    Tighten the nuts to 40 N·m (30 lb ft).


    Object Number: 1949877  Size: SH
  20. Connect the right post-catalytic converter HO2S electrical connector (1).

  21. Object Number: 1949882  Size: SH
  22. Connect the left post-catalytic converter HO2S electrical connector (1).

  23. Object Number: 1947045  Size: SH
  24. Connect the left rear muffler (1) to the intermediate exhaust assembly (2).
  25. Notice: Refer to Fastener Notice in the Preface section.

  26. Install the left rear muffler to intermediate exhaust assembly retaining bolts (3).
  27. Tighten
    Tighten the bolts to 45 N·m (33 lb ft).

  28. 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 .
  29. Lower the vehicle to the ground.
  30. Connect the battery ground cable to the battery. Refer to Battery Negative Cable Disconnection and Connection .
  31. If re-programming is required. Refer to Control Module References .
  32. Perform diagnostic system check using diagnostic scan tool, clear all relative DTCs and inspect the system for correct operation.

Removal Procedure - From 31 May 2007

  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.

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

  3. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle .
  4. Support the exhaust system using a suitable jack.
  5. Remove the rear exhaust muffler assemblies. Refer to Exhaust Muffler Replacement - Left Side and Exhaust Muffler Replacement - Right Side .
  6. Notice: Refer to Heated Oxygen and Oxygen Sensor Notice in the Preface section.


    Object Number: 1949882  Size: SH
  7. Disconnect the left post-catalytic converter heated oxygen sensor (HO2S) electrical connector (1).

  8. Object Number: 1949877  Size: SH
  9. Disconnect the right post-catalytic converter 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: 1947044  Size: SH

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

  15. Remove the intermediate exhaust assembly to right catalytic converter retaining nuts (3).
  16. Discard the nuts.

  17. Disconnect the intermediate exhaust assembly (2) from the right catalytic converter (1).

  18. Object Number: 1947045  Size: SH
  19. Remove the intermediate exhaust assembly to rear muffler retaining bolts (3).

  20. Object Number: 1947047  Size: SH
  21. Detach the intermediate exhaust assembly (2) by removing the centre insulator hanger bracket to differential retaining bolt (1).
  22. Carefully lower the intermediate exhaust assembly from the vehicle.
  23. Remove the left post-catalytic converter HO2S. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 or Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 .
  24. Remove the right post-catalytic converter HO2S. Refer to Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 or Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 .

Installation Procedure - From 31 May 2007

  1. Clean all threads and flange faces of the intermediate exhaust system.
  2. Always check the condition of the catalytic converter to intermediate pipe flange gaskets and replace as necessary.
  3. Install the left post-catalytic converter HO2S to the intermediate exhaust system. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 or Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 .
  4. Install the right post-catalytic converter HO2S to the intermediate exhaust system. Refer to Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 or Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 .
  5. Notice: Refer to Exhaust System Inspection Notice in the Preface section.

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

  6. Position the intermediate exhaust assembly to the vehicle using a suitable jack.

  7. Object Number: 1947047  Size: SH
  8. Attach the intermediate exhaust assembly (2) by installing the centre insulator hanger bracket to differential retaining bolt (1).
  9. Tighten the intermediate exhaust assembly to rear muffler retaining bolts.
  10. Tighten
    Tighten the bolts to 45 N·m (33 lb ft).


    Object Number: 1947044  Size: SH
  11. Align the intermediate exhaust assembly (2) to the right catalytic converter (1).
  12. Notice: Refer to Fastener Notice in the Preface section.

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


    Object Number: 1947042  Size: SH
  15. Align the intermediate exhaust assembly (2) to the left catalytic converter (1).
  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: 1949877  Size: SH
  18. Connect the right post-catalytic converter HO2S electrical connector (1).

  19. Object Number: 1949882  Size: SH
  20. Connect the left post-catalytic converter HO2S electrical connector (1).

  21. Object Number: 1947045  Size: SH
  22. Connect the left rear muffler (1) to the intermediate exhaust assembly (2).
  23. Notice: Refer to Fastener Notice in the Preface section.

  24. Install the left rear muffler to intermediate exhaust assembly retaining bolts (3).
  25. Tighten
    Tighten the bolts to 45 N·m (33 lb ft).

  26. 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 .
  27. Lower the vehicle to the ground.
  28. Connect the battery ground cable to the battery. Refer to Battery Negative Cable Disconnection and Connection .
  29. If re-programming is required. Refer to Control Module References .
  30. Perform diagnostic system check using diagnostic scan tool, clear all relative DTCs and inspect the system for correct operation.