GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2004 🢒 GTO 🢒 Engine 🢒 Engine Controls - 5.7L 🢒 Catalytic Converter Replacement

Removal Procedure

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

    Caution: Refer to Battery Disconnect Caution in the Preface section.

  1. Disconnect the negative battery cable.
  2. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  3. Remove the oxygen sensors. Refer to the following in Engine Controls:
    4. •  Heated Oxygen Sensor Replacement - Bank 1 Sensor 1
    •  Heated Oxygen Sensor Replacement - Bank 1 Sensor 2
    •  Heated Oxygen Sensor Replacement - Bank 2 Sensor 1
    •  Heated Oxygen Sensor Replacement - Bank 2 Sensor 2

    Object Number: 1343060 Size: SH
  4. On vehicles with automatic transmission, remove the exhaust support brace bracket bolts (1).

    5. Object Number: 1343065 Size: SH
  5. On vehicles with manual transmission, remove the exhaust support brace bracket bolts (1).
  6. Support the muffler assembly with a jackstand.

    7. Object Number: 1343069 Size: SH
  7. Remove the catalytic converter to muffler flange bolts (1).
  8. Separate the catalytic converter and muffler assemblies then remove the flange gasket (2), from the flange joint.

    9. Object Number: 1343074 Size: SH
  9. Support the catalytic converter assembly with a jackstand, then remove the catalytic converter to exhaust manifold flange retaining nuts (1).
  10. Remove the catalytic converter assembly from the vehicle.

Installation Procedure
  1. Position the catalytic converter assembly to the vehicle.
  2. Support the catalytic converter assembly with a jackstand.

    3. Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 1343074 Size: SH
  3. Install the catalytic converter to exhaust manifold flange retaining nuts (1).

    4. Tighten
    Tighten the catalytic converter to exhaust manifold flange bolts to 25 N·m (18 lb ft).


    Object Number: 1343069 Size: SH
  4. Install a new catalytic converter to muffler flange gasket (2).
  5. Install the catalytic converter to muffler flange bolts (1).

    6. Tighten
    Tighten the catalytic converter to muffler flange bolts to 45 N·m (33 lb ft).


    Object Number: 1343065 Size: SH
  6. On vehicles with manual transmission, install the exhaust support brace bracket bolts (1).

    7. Tighten
    Tighten the exhaust support brace bracket bolts to 35 N·m (26 lb ft).


    Object Number: 1343060 Size: SH
  7. On vehicles with automatic transmission, install the exhaust support brace bracket bolts (1).

    8. Tighten
    Tighten the exhaust support brace bracket bolts to 35 N·m (26 lb ft).

  8. Install the oxygen sensors. Refer to the following in Engine Controls:
    9. •  Heated Oxygen Sensor Replacement - Bank 1 Sensor 1
    •  Heated Oxygen Sensor Replacement - Bank 1 Sensor 2
    •  Heated Oxygen Sensor Replacement - Bank 2 Sensor 1
    •  Heated Oxygen Sensor Replacement - Bank 2 Sensor 2
  9. Lower the vehicle.

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

    Caution: Refer to Battery Disconnect Caution in the Preface section.

  10. Connect the negative battery cable.