GM Service Manual Online
For 1990-2009 cars only

Catalytic Converter Replacement RWD

Removal Procedure

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

Caution: Refer to Protective Goggles and Glove Caution in the Preface section.

  1. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.

  2. Object Number: 1363915  Size: SH
  3. Disconnect the heated oxygen sensor (HO2S) at the sensor pigtail (3).
  4. Remove the HO2S if replacement is necessary. Refer to Heated Oxygen Sensor 2 Replacement in Engine Controls - 2.8L (LK5) or Heated Oxygen Sensor 2 Replacement in Engine Controls - 3.5L (L52).

  5. Object Number: 753687  Size: SH
  6. Remove the nuts securing the muffler to the catalytic converter.
  7. Position the muffler rearward, enough to allow the studs located in the front to clear the catalytic converter pipe flange.

  8. Object Number: 1313621  Size: SH
  9. Remove the 3 nuts attaching the catalytic converter to the exhaust manifold.
  10. Lower the catalytic converter from the vehicle.

  11. Object Number: 1313620  Size: SH
  12. Remove the exhaust manifold seal from the exhaust manifold flange. Discard the seal.

Installation Procedure


    Object Number: 1313620  Size: SH
  1. Install the NEW seal to the exhaust manifold flange.
  2. Notice: Refer to Exhaust System Inspection Notice in the Preface section.


    Object Number: 1313621  Size: SH
  3. Position the catalytic converter to the exhaust manifold.
  4. Install the 3 nuts attaching the catalytic converter to the exhaust manifold. Do not tighten at this time.

  5. Object Number: 753687  Size: SH
  6. Align the catalytic converter with the studs located in the front of the muffler.
  7. Notice: Refer to Fastener Notice in the Preface section.

  8. Install the 2 nuts securing the muffler to the catalytic converter.
  9. Tighten

    1. Tighten the muffler nuts by hand until each contacts the metal flange.
    2. Tighten the muffler nuts to 45 N·m (33 lb ft).
    3. Tighten the catalytic converter nuts previously installed in step 3 to 50 N·m (37 lb ft).
  10. Install the HO2S if previously removed. Refer to Heated Oxygen Sensor 2 Replacement in Engine Controls - 2.8L (LK5) or Heated Oxygen Sensor 2 Replacement in Engine Controls - 3.5L (L52).

  11. Object Number: 1363915  Size: SH
  12. Connect the HO2S at the sensor pigtail (3).
  13. Lower the vehicle.

Catalytic Converter Replacement 4WD

Removal Procedure

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

Caution: Refer to Protective Goggles and Glove Caution in the Preface section.

  1. Remove the right torsion bar. Refer to Torsion Bar Replacement in Front Suspension.

  2. Object Number: 1363915  Size: SH
  3. Disconnect the heated oxygen sensor (HO2S) at the sensor pigtail (3).
  4. Remove the HO2S if replacement is necessary. Refer to Heated Oxygen Sensor 2 Replacement in Engine Controls - 2.8L (LK5) or Heated Oxygen Sensor 2 Replacement in Engine Controls - 3.5L (L52).

  5. Object Number: 753687  Size: SH
  6. Remove the nuts securing the muffler to the catalytic converter.
  7. Position the muffler rearward enough to allow the studs located in the front to clear the catalytic converter pipe flange.

  8. Object Number: 1313621  Size: SH
  9. Remove the 3 nuts attaching the catalytic converter to the exhaust manifold.
  10. Lower the catalytic converter from the vehicle.

  11. Object Number: 1313620  Size: SH
  12. Remove the exhaust manifold seal from the exhaust manifold flange. Discard the seal.

Installation Procedure


    Object Number: 1313620  Size: SH
  1. Install the NEW seal to the exhaust manifold flange.
  2. Notice: Refer to Exhaust System Inspection Notice in the Preface section.


    Object Number: 1313621  Size: SH
  3. Position the catalytic converter to the exhaust manifold.
  4. Install the 3 nuts attaching the catalytic converter to the exhaust manifold. Do not tighten at this time.

  5. Object Number: 753687  Size: SH
  6. Align the catalytic converter with the studs located in the front of the muffler.
  7. Notice: Refer to Fastener Notice in the Preface section.

  8. Install the 2 nuts securing the muffler to the catalytic converter.
  9. Tighten

    1. Tighten the muffler nuts by hand until each contacts the metal flange.
    2. Tighten the muffler nuts to 45 N·m (33 lb ft).
    3. Tighten the catalytic converter nuts previously installed in step 3 to 50 N·m (37 lb ft).
  10. Install the HO2S if previously removed. Refer to Heated Oxygen Sensor 2 Replacement in Engine Controls - 2.8L (LK5) or Heated Oxygen Sensor 2 Replacement in Engine Controls - 3.5L (L52).

  11. Object Number: 1363915  Size: SH
  12. Connect the HO2S at the sensor pigtail (3).
  13. Install the right torsion bar. Refer to Torsion Bar Replacement in Front Suspension.