GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2004 🢒 SSR 🢒 Engine 🢒 Engine Exhaust 🢒 Catalytic Converter Replacement

Removal Procedure
  1. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  2. Unclip the oxygen sensor connection from the floor reinforcement.

    3. Object Number: 664828 Size: SH
  3. Remove the oxygen sensor clips from the frame.
  4. Disconnect the connector position assurance (CPA) retainers.
  5. Disconnect the oxygen sensor electrical connectors.

    6. Object Number: 664951 Size: SH
  6. Unclip the oxygen sensors electrical connectors from the following:
    7. • Hose clip
    • Transmission crossmember
  7. Disconnect the CPA retainers.
  8. Disconnect the oxygen sensor electrical connectors (1, 2).

    9. Object Number: 858550 Size: SH
  9. Remove the left exhaust manifold pipe nuts.

    10. Object Number: 858553 Size: SH
  10. Remove the right exhaust manifold pipe nuts.

    11. Object Number: 1231421 Size: SH
  11. Remove the exhaust muffler nuts.

    12. Object Number: 1231424 Size: SH
  12. Remove the transmission support. Refer to Transmission Support Replacement in Frame and Underbody.
  13. Remove the catalytic converter.

    14. Object Number: 664954 Size: SH
  14. If necessary, remove the oxygen sensors.

Installation Procedure

    Object Number: 664954 Size: SH
  1. If necessary, install the oxygen sensors.
    2. 1.1. Apply anti-seize compound GM P/N 12377953 or equivalent to the threads of the old oxygen sensors.

    Notice: Refer to Fastener Notice in the Preface section.

    1.2. Install the oxygen sensors.

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


    Object Number: 1231424 Size: SH
  2. Install the catalytic convertor.
  3. Install the transmission support. Refer to Transmission Support Replacement in Frame and Underbody.

    4. Object Number: 858553 Size: SH
  4. Install NEW exhaust manifold pipe seals to the exhaust manifolds.
  5. Install the right exhaust manifold pipe nuts until snug.

    6. Object Number: 858550 Size: SH
  6. Install the left exhaust manifold pipe nuts until snug.
  7. Tighten the exhaust manifold pipe nuts.

    8. Tighten
    Tighten the nuts to 50 N·m (37 lb ft).


    Object Number: 1231421 Size: SH
  8. Install the exhaust muffler nuts.

    9. Tighten
    Tighten the nuts to 45 N·m (33 lb ft).


    Object Number: 664951 Size: SH
  9. Connect the oxygen sensor electrical connectors (1, 2).
  10. Connect the CPA retainers.
  11. Clip the oxygen sensors electrical connectors to the following:
    12. • Hose clip
    • Transmission crossmember

    Object Number: 664828 Size: SH
  12. Connect the oxygen sensor electrical connectors.
  13. Connect the CPA retainers.
  14. Install the clip around the engine harness and the oxygen sensor pigtail.
  15. Clip the oxygen sensor connection to the floor reinforcement.
  16. Lower the vehicle.