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For 1990-2009 cars only

Catalytic Converter Replacement Heavy Duty-6.0L

Removal Procedure

  1. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  2. Remove the protective shields as necessary.
  3. Remove the rear exhaust system. Refer to Rear Exhaust System Replacement .

  4. Object Number: 313264  Size: SH
  5. Disconnect the electrical connector from the oxygen sensor.

  6. Object Number: 309165  Size: SH
  7. Remove the nuts from the left exhaust manifold.

  8. Object Number: 344260  Size: SH
  9. Remove the left side catalytic converter.
  10. Transfer the oxygen sensors if the catalytic converter is to be replaced. Refer to Heated Oxygen Sensor Replacement - Bank 2 in Engine Controls.

Installation Procedure


    Object Number: 344260  Size: SH
  1. Install the new exhaust seals to the exhaust manifold.
  2. Install the left side catalytic converter.

  3. Object Number: 309165  Size: SH

    Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  4. Install the new nuts to the left side exhaust manifold.
  5. Tighten
    Tighten the exhaust manifold nuts to 50 N·m (39 lb ft).


    Object Number: 313264  Size: SH
  6. Connect the electrical connector to the oxygen sensor.
  7. Install the rear exhaust system. Refer to Rear Exhaust System Replacement .
  8. Remove the safety stands
  9. Lower the vehicle.

Catalytic Converter Replacement 4.8L and 5.3L Engines

Removal Procedure


    Object Number: 349061  Size: SH
  1. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  2. Remove the engine shield bolts and shield, if necessary.

  3. Object Number: 339429  Size: SH
  4. Remove the oil pan skid plate bolts and plate, if necessary.

  5. Object Number: 647997  Size: SH
  6. Support the transmission with a suitable transmission jack.
  7. Remove the transmission mount to transmission support nuts.
  8. Raise the transmission off the transmission support.

  9. Object Number: 702036  Size: SH
  10. Remove the transmission support crossmember bolts and nuts.
  11. Remove the transmission support crossmember.

  12. Object Number: 665019  Size: SH
  13. Unclip the oxygen sensor connection from the floor reinforcement.

  14. Object Number: 664828  Size: SH
  15. Remove the clip from around the engine harness and the oxygen sensor pigtail.
  16. Disconnect the connector position assurance (CPA) retainers.
  17. Disconnect the oxygen sensor electrical connectors.

  18. Object Number: 664951  Size: SH
  19. Unclip the oxygen sensors electrical connectors from the following:
  20. • Hose clip
    • Transmission crossmember
  21. Disconnect the CPA retainers.
  22. Disconnect the oxygen sensor electrical connectors (1, 2).

  23. Object Number: 664832  Size: SH
  24. Remove the left exhaust manifold pipe nuts.

  25. Object Number: 664837  Size: SH
  26. Remove the right exhaust manifold pipe nuts.

  27. Object Number: 664840  Size: SH
  28. Remove the exhaust muffler nuts.
  29. Remove the catalytic converter.

  30. Object Number: 664954  Size: SH
  31. Remove the oxygen sensors if the catalytic converter is to be replaced.

Installation Procedure

    Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 664954  Size: SH
  1. If the catalytic converter was replaced, perform the following:
  2. 1.1. Apply anti-seize compound GM P/N 12377953 or equivalent to the threads of the old oxygen sensors.
    1.2. Install the oxygen sensors.

    Tighten
    Tighten the oxygen sensors to 42 N·m (31 lb ft).

  3. Install the catalytic convertor.

  4. Object Number: 664837  Size: SH
  5. Install NEW exhaust manifold pipe seals to the exhaust manifolds.
  6. Install the right exhaust manifold pipe nuts until sung.

  7. Object Number: 664832  Size: SH
  8. Install the left exhaust manifold pipe nuts until snug.
  9. Tighten the right and left exhaust manifold pipe nuts.
  10. Tighten
    Tighten the nuts to 50 N·m (39 lb ft).


    Object Number: 664840  Size: SH
  11. Install the exhaust muffler nuts.
  12. Tighten
    Tighten the nuts to 40 N·m (30 lb ft).


    Object Number: 664951  Size: SH
  13. Connect the oxygen sensor electrical connectors (1, 2).
  14. Connect the CPA retainers.
  15. Clip the oxygen sensors electrical connectors to the following:
  16. • Hose clip
    • Transmission crossmember

    Object Number: 664828  Size: SH
  17. Connect the oxygen sensor electrical connectors.
  18. Connect the CPA retainers.
  19. Install the clip around the engine harness and the oxygen sensor pigtail.

  20. Object Number: 665019  Size: SH
  21. Clip the oxygen sensor connection to the floor reinforcement.

  22. Object Number: 702036  Size: SH
  23. Install the transmission support crossmember.
  24. Install the transmission support crossmember bolts and nuts.
  25. Tighten
    Tighten the bolts to 95 N·m (70 lb ft).


    Object Number: 647997  Size: SH
  26. Lower the transmission onto the transmission support.
  27. Install the transmission mount to transmission support nuts.
  28. Tighten
    Tighten the nuts to 40 N·m (30 lb ft).

  29. Remove the transmission jack.

  30. Object Number: 339429  Size: SH
  31. Install the oil pan skid plate and bolts, if necessary.
  32. Tighten
    Tighten the bolts to 20 N·m (15 lb ft).


    Object Number: 349061  Size: SH
  33. Install the engine shield and bolts, if necessary.
  34. Tighten
    Tighten the bolts to 20 N·m (15 lb ft).

  35. Lower the vehicle.