GM Service Manual Online
For 1990-2009 cars only

Catalytic Converter Replacement - Right Side LZ4

Removal Procedure

Important: The catalytic converter is serviced by replacing the entire assembly. Always replace the gaskets at the front and rear flanges when servicing the catalytic converter. Never install the original gasket.


    Object Number: 1886100  Size: SH
  1. Remove the heated oxygen sensor (HO2S). Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 .
  2. Lower the vehicle.
  3. Remove the right side exhaust manifold heat shield bolts (1).
  4. Remove the right side exhaust manifold heat shield.

  5. Object Number: 1886115  Size: SH
  6. Remove the right side catalytic converter to exhaust manifold nuts (1).
  7. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle .
  8. Support the exhaust system.

  9. Object Number: 1886121  Size: SH
  10. Remove the catalytic converter to muffler nuts (1).
  11. Reposition the muffler assembly rearward until the catalytic converter can be removed.
  12. Remove the catalytic converter.
  13. Remove the catalytic converter gaskets.
  14. Clean and inspect the exhaust manifold and the exhaust pipe gasket mating surfaces.

Installation Procedure


    Object Number: 1886121  Size: SH
  1. Install the catalytic converter gasket onto the catalytic converter.
  2. Reposition the muffler assembly rearward until the catalytic converter can be installed.
  3. Install the catalytic converter.
  4. Notice: Refer to Fastener Notice in the Preface section.

  5. Install the catalytic converter nuts (1).
  6. Tighten
    Tighten the nuts to 60 N·m (44 lb ft).

  7. Remove the support from the exhaust system.

  8. Object Number: 1886115  Size: SH
  9. Install the right side catalytic converter to exhaust manifold nuts (1).
  10. Tighten
    Tighten the nuts to 35 N·m (26 lb ft).


    Object Number: 1886100  Size: SH
  11. Install the right side exhaust manifold heat shield.
  12. Install the right side exhaust manifold heat shield bolts (1).
  13. Tighten
    Tighten the nuts to 10 N·m (89 lb in).


    Object Number: 1886100  Size: SH
  14. Install the exhaust manifold heat shield.
  15. Install the right side exhaust manifold heat shield bolts (1).
  16. Tighten
    Tighten the nuts to 10 N·m (89 lb in).

  17. Install the HO2S sensor. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 .

Catalytic Converter Replacement - Right Side LY7

Removal Procedure

Important: The catalytic converter is serviced by replacing the entire assembly. Always replace the gaskets at the front and rear flanges when servicing the catalytic converter. Never install the original gasket.


    Object Number: 1888732  Size: SH
  1. Remove the heated oxygen sensor (HO2S). Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 .
  2. Lower the vehicle.
  3. Disconnect the engine wiring harness electrical connector from the HO2S electrical connector (1)

  4. Object Number: 1888860  Size: SH
  5. Remove the right side exhaust manifold heat shield bolts (1).
  6. Remove the right side exhaust manifold heat shield.

  7. Object Number: 1886115  Size: SH
  8. Remove the right side catalytic converter to exhaust manifold nuts (1).
  9. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle .
  10. Support the exhaust system.

  11. Object Number: 1886121  Size: SH
  12. Remove the catalytic converter to intermediate muffler nuts (1).
  13. Reposition the muffler assembly rearward until the catalytic converter can be removed.
  14. Remove the catalytic converter.
  15. Remove the catalytic converter gaskets.
  16. Clean and inspect the exhaust manifold and the exhaust pipe gasket mating surfaces.

Installation Procedure


    Object Number: 1886121  Size: SH
  1. Install the catalytic converter gasket onto the catalytic converter.
  2. Reposition the muffler assembly rearward until the catalytic converter can be installed.
  3. Install the catalytic converter.
  4. Notice: Refer to Fastener Notice in the Preface section.

  5. Install the catalytic converter to intermediate muffler nuts (1).
  6. Tighten
    Tighten the nuts to 60 N·m (44 lb ft).

  7. Remove the support from the exhaust system.

  8. Object Number: 1886115  Size: SH
  9. Install the right side catalytic converter to exhaust manifold nuts (1).
  10. Tighten
    Tighten the nuts to 35 N·m (26 lb ft).


    Object Number: 1886100  Size: SH
  11. Install the right side exhaust manifold heat shield.
  12. Install the right side exhaust manifold heat shield bolts (1).
  13. Tighten
    Tighten the nuts to 10 N·m (89 lb in).


    Object Number: 1888860  Size: SH
  14. Install the exhaust manifold heat shield.
  15. Install the right side exhaust manifold heat shield bolts (1).
  16. Tighten
    Tighten the nuts to 10 N·m (89 lb in).


    Object Number: 1888732  Size: SH
  17. Connect the engine wiring harness electrical connector to the HO2S electrical connector (1)
  18. Install the HO2S sensor. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 2.

Catalytic Converter Replacement - Right Side LZ4

Removal Procedure

Note: The catalytic converter is serviced by replacing the entire assembly. Always replace the gaskets at the front and rear flanges when servicing the catalytic converter. Never install the original gasket.


    Object Number: 1886100  Size: SH
  1. Remove the heated oxygen sensor (HO2S). Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 2.
  2. Lower the vehicle.
  3. Remove the right side exhaust manifold heat shield bolts (1).
  4. Remove the right side exhaust manifold heat shield.

  5. Object Number: 1886115  Size: SH
  6. Remove the right side catalytic converter to exhaust manifold nuts (1).
  7. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle.
  8. Support the exhaust system.

  9. Object Number: 1886121  Size: SH
  10. Remove the catalytic converter to muffler nuts (1).
  11. Reposition the muffler assembly rearward until the catalytic converter can be removed.
  12. Remove the catalytic converter.
  13. Remove the catalytic converter gaskets.
  14. Clean and inspect the exhaust manifold and the exhaust pipe gasket mating surfaces.

Installation Procedure

    Caution: Refer to Fastener Caution in the Preface section.


    Object Number: 1886115  Size: SH
  1. Install the right side catalytic converter to exhaust manifold nuts (1) and tighten to 35 N·m (26 lb ft).

  2. Object Number: 1886100  Size: SH
  3. Install the right side exhaust manifold heat shield.
  4. Install the right side exhaust manifold heat shield bolts (1) and tighten to 10 N·m (89 lb in).

  5. Object Number: 1886100  Size: SH
  6. Install the exhaust manifold heat shield.
  7. Install the right side exhaust manifold heat shield bolts (1) and tighten to 10 N·m (89 lb in).
  8. Install the HO2S sensor. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 2.

Catalytic Converter Replacement - Right Side LY7

Removal Procedure

Note: The catalytic converter is serviced by replacing the entire assembly. Always replace the gaskets at the front and rear flanges when servicing the catalytic converter. Never install the original gasket.


    Object Number: 1888732  Size: SH
  1. Remove the heated oxygen sensor (HO2S). Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 2.
  2. Lower the vehicle.
  3. Disconnect the engine wiring harness electrical connector from the HO2S electrical connector (1)

  4. Object Number: 1888860  Size: SH
  5. Remove the right side exhaust manifold heat shield bolts (1).
  6. Remove the right side exhaust manifold heat shield.

  7. Object Number: 1886115  Size: SH
  8. Remove the right side catalytic converter to exhaust manifold nuts (1).
  9. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle.
  10. Support the exhaust system.

  11. Object Number: 1886121  Size: SH
  12. Remove the catalytic converter to intermediate muffler nuts (1).
  13. Reposition the muffler assembly rearward until the catalytic converter can be removed.
  14. Remove the catalytic converter.
  15. Remove the catalytic converter gaskets.
  16. Clean and inspect the exhaust manifold and the exhaust pipe gasket mating surfaces.

Installation Procedure


    Object Number: 1886121  Size: SH
  1. Install the catalytic converter gasket onto the catalytic converter.
  2. Reposition the muffler assembly rearward until the catalytic converter can be installed.
  3. Install the catalytic converter.
  4. Caution: Refer to Fastener Caution in the Preface section.

  5. Install the catalytic converter to intermediate muffler nuts (1) and tighten to 60 N·m (44 lb ft).
  6. Remove the support from the exhaust system.

  7. Object Number: 1886115  Size: SH
  8. Install the right side catalytic converter to exhaust manifold nuts (1) and tighten to 35 N·m (26 lb ft).

  9. Object Number: 1886100  Size: SH
  10. Install the right side exhaust manifold heat shield.
  11. Install the right side exhaust manifold heat shield bolts (1) and tighten to 10 N·m (89 lb in).

  12. Object Number: 1888860  Size: SH
  13. Install the exhaust manifold heat shield.
  14. Install the right side exhaust manifold heat shield bolts (1) and tighten to 10 N·m (89 lb in).

  15. Object Number: 1888732  Size: SH
  16. Connect the engine wiring harness electrical connector to the HO2S electrical connector (1)
  17. Install the HO2S sensor. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 2.

Catalytic Converter Replacement - Right Side LCS

Removal Procedure

Note: The catalytic converter is serviced by replacing the entire assembly. Always replace the gaskets at the front and rear flanges when servicing the catalytic converter. Never install the original gasket.


    Object Number: 1888732  Size: SH
  1. Remove the heated oxygen sensor (HO2S). Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 2.
  2. Lower the vehicle.
  3. Disconnect the engine wiring harness electrical connector from the HO2S electrical connector (1)

  4. Object Number: 1888860  Size: SH
  5. Remove the right side exhaust manifold heat shield bolts (1).
  6. Remove the right side exhaust manifold heat shield.

  7. Object Number: 2124810  Size: SH
  8. Remove the right side catalytic converter to exhaust manifold nuts (1, 2 and 3).
  9. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle.
  10. Support the exhaust system.

  11. Object Number: 2124830  Size: SH
  12. Remove the catalytic converter to intermediate muffler nuts (1).
  13. Reposition the muffler assembly rearward until the catalytic converter (2) can be removed.
  14. Remove the catalytic converter.
  15. Remove the catalytic converter gaskets.
  16. Clean and inspect the exhaust manifold and the exhaust pipe gasket mating surfaces.

Installation Procedure


    Object Number: 2124830  Size: SH
  1. Install the catalytic converter gasket onto the catalytic converter.
  2. Reposition the muffler assembly rearward until the catalytic converter (2) can be installed.
  3. Install the catalytic converter.
  4. Caution: Refer to Fastener Caution in the Preface section.

  5. Install the catalytic converter to intermediate muffler nuts (1) and tighten to 60 N·m (44 lb ft).
  6. Remove the support from the exhaust system.

  7. Object Number: 2124810  Size: SH
  8. Tighten the right side catalytic converter to exhaust manifold nuts in the following sequence.
  9. 6.1. Tighten the nut (1) to 35 N·m (26 lb ft)
    6.2. Tighten the nut (2) to 35 N·m (26 lb ft)
    6.3. Tighten the nut (3) to 35 N·m (26 lb ft)

    Object Number: 1886100  Size: SH
  10. Install the right side exhaust manifold heat shield.
  11. Install the right side exhaust manifold heat shield bolts (1) and tighten to 10 N·m (89 lb in).

  12. Object Number: 1888860  Size: SH
  13. Install the exhaust manifold heat shield.
  14. Install the right side exhaust manifold heat shield bolts (1) and tighten to 10 N·m (89 lb in).

  15. Object Number: 1888732  Size: SH
  16. Connect the engine wiring harness electrical connector to the HO2S electrical connector (1)
  17. Install the HO2S sensor. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 2.