GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2007 🢒 Express - AWD 🢒 Engine 🢒 Engine Exhaust 🢒 Catalytic Converter Replacement

Catalytic Converter Replacement Single Exhaust - 4.3L, 4.8L and 5.3L

Removal Procedure

    Object Number: 313264 Size: SH
  1. Raise the vehicle. Refer to Lifting and Jacking the Vehicle .
  2. Disconnect the heated oxygen sensor (HO2S) electrical connections from catalytic converter pipe.
  3. Remove the exhaust hanger bolts and hanger from the transmission.
  4. Remove the nuts and the seals retaining the catalytic converter pipe to the exhaust manifolds.

    5. Object Number: 1202609 Size: SH

    Caution: In order to avoid being burned, do not service the exhaust system while it is still hot. Service the system when it is cool.

    Caution: Always wear protective goggles and gloves when removing exhaust parts as falling rust and sharp edges from worn exhaust components could result in serious personal injury.

  5. Remove the flange nuts from the catalytic pipe to the muffler.
  6. Remove the catalytic converter from the vehicle.
  7. Remove the oxygen sensors as necessary. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 .

Installation Procedure

    Object Number: 1202609 Size: SH
  1. Install the oxygen sensors as necessary. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 .
  2. Position the catalytic pipe to the vehicle.
  3. Install the retaining nuts to the front of the muffler.

    4. Do not tighten the nuts.

    Notice: Refer to Fastener Notice in the Preface section.

  4. Install the new seals, the nuts and the exhaust pipe flange to exhaust manifold.

    5. Tighten

        • Tighten the exhaust pipe flange to exhaust manifold nuts to 65 N·m (48 lb ft).
        • Tighten the catalytic converter to muffler retaining nuts to 48 N·m (35 lb ft).

    Object Number: 313264 Size: SH
  5. Connect the HO2S electrical connections.
  6. Install the exhaust hanger and bolts to the transmission.

    7. Tighten
    Tighten the bolts to 17 N·m (13 lb ft).

    Notice: When inspecting or replacing exhaust system components, make sure there is adequate clearance from all points on the underbody to prevent overheating of the floor pan and possible damage to the passenger compartment insulation and trim materials.

  7. Verify the exhaust system for proper clearance and the alignment of all components.
  8. Lower the vehicle.

Catalytic Converter Replacement 6.0L - Right

Removal Procedure

    Object Number: 1202601 Size: SH
  1. Raise the vehicle. Refer to Lifting and Jacking the Vehicle .
  2. Disconnect the oxygen sensor connectors.
  3. Remove the exhaust hanger bolts and hanger from the vehicle.

    4. Caution: In order to avoid being burned, do not service the exhaust system while it is still hot. Service the system when it is cool.

    Caution: Always wear protective goggles and gloves when removing exhaust parts as falling rust and sharp edges from worn exhaust components could result in serious personal injury.

  4. Remove the nuts retaining the exhaust pipe flange to the catalytic converter pipe.
  5. Loosen the nut retaining the exhaust pipe clamp to the muffler.
  6. Remove the exhaust pipe and flange gasket.

Installation Procedure

    Notice: Refer to Fastener Notice in the Preface section.

  1. Remove the oxygen sensors and install into new exhaust pipe.

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


    Object Number: 1202601 Size: SH
  2. Install new gasket to the catalytic converter pipe flange.
  3. Install the exhaust pipe to the vehicle.
  4. Install the nuts for the catalytic converter pipe to exhaust pipe.

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

  5. Tighten the exhaust pipe clamp nut.

    6. Tighten
    Tighten the nut to 54 N·m (40 lb ft).

    Notice: When inspecting or replacing exhaust system components, make sure there is adequate clearance from all points on the underbody to prevent overheating of the floor pan and possible damage to the passenger compartment insulation and trim materials.

  6. Verify the exhaust system for proper clearance and the alignment of all components.
  7. Install the exhaust hanger and bolts.

    8. Tighten
    Tighten the bolts to 17 N·m (13 lb ft).

  8. Lower the vehicle.

Catalytic Converter Replacement 6.0L - Left

Removal Procedure

    Object Number: 1202601 Size: SH
  1. Raise the vehicle. Refer to Lifting and Jacking the Vehicle .
  2. Disconnect the oxygen sensors.
  3. Remove the exhaust hanger bolts and hanger from the vehicle.

    4. Caution: In order to avoid being burned, do not service the exhaust system while it is still hot. Service the system when it is cool.

    Caution: Always wear protective goggles and gloves when removing exhaust parts as falling rust and sharp edges from worn exhaust components could result in serious personal injury.

  4. Remove the nuts retaining the exhaust pipe flange to the catalytic converter pipe.
  5. Remove the nuts retaining the exhaust pipe flange to the muffler.
  6. Remove the exhaust pipe.
  7. Remove the flange gasket.

Installation Procedure

    Notice: Refer to Fastener Notice in the Preface section.

  1. Remove the oxygen sensors and install into the new exhaust pipe.

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


    Object Number: 1202601 Size: SH
  2. Install new gaskets to the muffler flange and the catalytic converter pipe flange.
  3. Install the exhaust pipe.
  4. Install the nuts for the catalytic converter pipe to the exhaust pipe.

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

  5. Install the nuts for the muffler to the exhaust pipe.

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

  6. Connect the oxygen sensor connectors.
  7. Install the exhaust hanger and bolts.

    8. Tighten
    Tighten the bolts to 17 N·m (13 lb ft).

    Notice: When inspecting or replacing exhaust system components, make sure there is adequate clearance from all points on the underbody to prevent overheating of the floor pan and possible damage to the passenger compartment insulation and trim materials.

  8. Verify the exhaust system for proper clearance and the alignment of all components.
  9. Lower the vehicle.

Catalytic Converter Replacement 6.6L (LBZ/LLY)

Removal Procedure

    Object Number: 647997 Size: SH
  1. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle .
  2. Support the transmission with a suitable transmission jack.
  3. Remove the transmission mount to transmission support nuts.
  4. Raise the transmission off of the transmission support.

    5. Object Number: 788013 Size: SH
  5. Remove the transmission support crossmember bolts.
  6. Remove the transmission support crossmember.

    7. Object Number: 1862862 Size: SH
  7. Remove the catalytic converter to muffler nuts (3).

    8. Object Number: 668379 Size: SH
  8. Loosen the exhaust pipe clamp.
  9. Slide the exhaust pipe clamp up onto the exhaust pipe adapter.

    10. Object Number: 1862864 Size: SH
  10. Slide the catalytic converter hanger out of the exhaust pipe hanger bracket and remove the catalytic converter.

Installation Procedure

    Object Number: 1862864 Size: SH
  1. Install the catalytic converter.
  2. Apply water based lubricant to the exhaust pipe hanger bracket, in order to aid in installation.
  3. Slide the catalytic converter hanger into the exhaust pipe hanger bracket.

    4. Object Number: 1862862 Size: SH
  4. Install the catalytic converter to muffler nuts (3) until snug.

    5. Object Number: 668379 Size: SH

    Important: Ensure that the manifold pipe is square to the exhaust pipe adapter.

  5. Slide the exhaust pipe clamp down and around the pipe connection.

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

  6. Tighten the exhaust pipe clamp and catalytic converter nuts.

    7. Tighten

        • Tighten the clamp to 40 N·m (30 lb ft).
        • Tighten the nuts to 40 N·m (30 lb ft).

    Object Number: 647997 Size: SH
  7. Lower the transmission onto the transmission support.
  8. Install the transmission mount to transmission support nuts.

    9. Tighten
    Tighten the bolts to 40 N·m (30 lb ft).

  9. Remove the support from the transmission.
  10. Lower the vehicle.

Catalytic Converter Replacement 6.6L - (LMM)

Removal Procedure
  1. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle.

    2. Object Number: 1862863 Size: SH
  2. Remove the catalytic converter (1) to particulate filter nuts (3).

    3. Object Number: 1862851 Size: SH
  3. Loosen the catalytic converter to exhaust pipe adaptor clamp (1).
  4. Slide the exhaust pipe clamp up onto the exhaust pipe adapter.

    5. Object Number: 2009405 Size: SH
  5. Remove the catalytic converter hanger to transmission bolts (1).
  6. With the catalytic converter hanger attached, remove the catalytic converter from the vehicle.
  7. Discard the catalytic converter to particulate filter gasket.
  8. If replacing the catalytic converter, remove the catalytic converter hanger.

Installation Procedure
  1. If replacing the catalytic converter, apply water based lubricant to the catalytic converter hanger bracket and slide the exhaust pipe hanger bracket into the catalytic converter hanger.

    2. Object Number: 2009405 Size: SH
  2. Install a NEW catalytic converter to particulate filter gasket.
  3. Position the catalytic converter to the Particulate filter, exhaust pipe adapter and transmission.

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

  4. Install the catalytic converter hanger to transmission bolts (1).

    5. Tighten
    Tighten the bolts to 34 N·m (25 lb ft).


    Object Number: 1862863 Size: SH
  5. Install the catalytic converter to particulate filter nuts (3) until snug.

    6. Object Number: 1862851 Size: SH

    Important: Ensure that the manifold pipe is square to the exhaust pipe adapter.

  6. Slide the exhaust pipe clamp (1) down and around the pipe connection.
  7. Tighten the exhaust pipe clamp and catalytic converter nuts.

    8. Tighten

        • Tighten the clamp to 40 N·m (30 lb ft).
        • Tighten the nuts to 40 N·m (30 lb ft).
  8. Lower the vehicle.