GM Service Manual Online
For 1990-2009 cars only

Catalytic Converter Replacement LNJ

Removal Procedure

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

  2. Object Number: 1370518  Size: SH
  3. Disconnect the heated oxygen sensor (HO2S) connector (2) from the wiring harness (3).

  4. Object Number: 926819  Size: SH
  5. Remove the catalytic converter pipe flange to exhaust system pipe flange nuts.
  6. Separate the pipes and discard the gasket.
  7. Important: Catalytic converter flex coupler must NEVER be deflected more than 6 degrees or failure of flex coupler could result.


    Object Number: 1370519  Size: SH
  8. Remove the nuts (3) securing the catalytic converter (4) to the exhaust manifold.
  9. Separate the catalytic converter flange from the exhaust manifold and discard the gasket (2).

  10. Object Number: 926825  Size: SH
  11. Separate the catalytic converter hanger from the rubber isolator and remove the catalytic converter from the vehicle.

  12. Object Number: 1370520  Size: SH
  13. Remove the exhaust manifold studs (1) if worn or damaged.
  14. If replacing the catalytic converter, remove the HO2S. Refer to Heated Oxygen Sensor 1 Replacement .

Installation Procedure

  1. Install the HO2S, if previously removed. Refer to Heated Oxygen Sensor 1 Replacement .
  2. Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 1370520  Size: SH
  3. Install the exhaust manifold studs (1) if previously removed.
  4. Tighten
    Tighten the studs to 6 N·m (53 lb in).


    Object Number: 926825  Size: SH
  5. Install the rubber isolator and to the catalytic converter hanger.

  6. Object Number: 1370519  Size: SH

    Notice: To prevent internal damage to the flexible coupling of the catalytic converter assembly, the converter must be supported. The vertical movement at the rear of the catalytic converter assembly must not exceed 6 degrees up or down.

  7. Install a new gasket (2) and attach the catalytic converter (4) to the exhaust manifold.
  8. Install the catalytic converter to the exhaust manifold nuts (3).
  9. Tighten
    Tighten the nuts to 37 N·m (27 lb ft).


    Object Number: 926819  Size: SH
  10. Install a new exhaust pipe flange gasket to the catalytic converter flange.
  11. Install the exhaust pipe to the catalytic converter pipe. with the catalytic converter nuts.
  12. Install the exhaust pipe to the catalytic converter pipe .
  13. Tighten
    Tighten the nuts to 37 N·m (27 lb ft).


    Object Number: 1370518  Size: SH
  14. Connect the HO2S connector (2) to the wiring harness (3).
  15. Lower the vehicle.