GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 HUMMER 🢒 2005 🢒 H2 🢒 Engine 🢒 Engine Exhaust 🢒 Catalytic Converter Replacement

Removal Procedure
  1. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle .
  2. Remove the catalytic converter guard. Refer to Catalytic Converter Guard Replacement .

    3. Object Number: 665040 Size: SH
  3. Disconnect the connector position assurance (CPA) retainers.
  4. Disconnect the oxygen sensor electrical connectors (1, 2).
  5. Remove the catalytic converter to muffler flange nuts.

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

    7. Object Number: 863015 Size: SH
  7. Remove the catalytic converter.

    8. Object Number: 664954 Size: SH
  8. 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).


    Object Number: 863015 Size: SH
  2. Install a NEW exhaust seal to the exhaust manifold.
  3. Install the catalytic converter.

    4. Object Number: 309165 Size: SH
  4. Install the left exhaust manifold pipe nuts.

    5. Tighten
    Tighten the exhaust manifold pipe nuts to 50 N·m (39 lb ft).

  5. Install the catalytic converter to muffler flange nuts.

    6. Tighten
    Tighten the nuts to 48 N·m (35 lb ft).


    Object Number: 665040 Size: SH
  6. Connect the oxygen sensor electrical connectors (1, 2).
  7. Connect the CPA retainers.

    8. Object Number: 794712 Size: SH
  8. Install the catalytic converter guard. Refer to Catalytic Converter Guard Replacement .
  9. Lower the vehicle.