GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 39194-C O2 Sensor Remover Tool

Removal Procedure


    Object Number: 898897  Size: SH
  1. Disconnect the intake air temperature (IAT) sensor connector.
  2. Loosen the clap at the air cleaner assembly.
  3. Remove the push-pin attachment from the outlet resonator/duct assembly to support the bracket.
  4. Loosen the clamp at the throttle body assembly.
  5. Disconnect the PCV fresh air vent hose at the cam cover.
  6. Remove the outlet resonator/duct assembly.

  7. Object Number: 951386  Size: SH
  8. Remove the exhaust manifold heat shield bolts.
  9. Remove the exhaust manifold heat shield.
  10. Disconnect the front and rear O2 sensor connectors. Remove the sensor if the exhaust manifold is being replaced using J 39194-C .
  11. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.

  12. Object Number: 898154  Size: SH
  13. Remove the exhaust manifold pipe to manifold nuts.
  14. Remove the exhaust manifold pipe to resonator pipe nuts behind the converter.
  15. Disconnect the rear O2 sensor wire from the heat shield.
  16. Separate the exhaust manifold pipe and resonator pipe. Discard the gaskets.

  17. Object Number: 746061  Size: SH
  18. Remove the exhaust manifold nuts.
  19. Remove the exhaust manifold assembly and discard the gasket.

  20. Object Number: 949143  Size: SH
  21. Remove the exhaust manifold gasket and discard.

Installation Procedure


    Object Number: 949143  Size: SH
  1. Install a new manifold gasket on the cylinder head.

  2. Object Number: 746061  Size: SH
  3. Install the exhaust manifold.
  4. Notice: Refer to Fastener Notice in the Preface section.

  5. Install the exhaust manifold nuts.
  6. Tighten
    Tighten the exhaust manifold-to-cylinder head nuts L61 to 18 N·m (13 lb ft).

  7. If necessary, transfer the O2 sensor from the old manifold.
  8. Important: Whenever the oxygen sensor is removed, coat the threads with nickel-based anti-seize compound such as Permatex® 77124, SA P/N 21485279 or equivalent.

  9. Install the O2 sensor into the exhaust manifold.
  10. Tighten
    Tighten the O2 sensor to 45 N·m (33 lb ft).


    Object Number: 926819  Size: SH
  11. Install the gasket and exhaust pipe to the intermediate pipe.
  12. Install the exhaust pipe-to-intermediate pipe nuts.
  13. Tighten
    Tighten the exhaust pipe-to-intermediate pipe nuts L61 to 30 N·m (22 lb ft).

  14. Attach the rear O2 sensor wire to the heat shield.

  15. Object Number: 898154  Size: SH
  16. Install a new exhaust manifold gasket onto the exhaust manifold flange studs.
  17. Position the exhaust manifold pipe onto the exhaust manifold studs and install the exhaust manifold nuts.
  18. Tighten
    Tighten the exhaust manifold pipe-to-exhaust manifold nuts L61 to 42 N·m (31 lb ft).


    Object Number: 951395  Size: SH
  19. Lower the vehicle.
  20. Install the exhaust manifold heat shield.
  21. Install the exhaust manifold heat shield bolts.
  22. Tighten
    Tighten the exhaust manifold heat shield bolts L61 to 23 N·m (17 lb ft).


    Object Number: 898897  Size: SH
  23. Install the outlet resonator/duct assembly into position.
  24. Connect the PVC fresh air vent hose assembly.
  25. Tighten the clamp at the throttle body assembly.
  26. Position the outlet resonator/duct assembly up with the support bracket and install the push-pin.
  27. Tighten the air cleaner assembly.
  28. Connect the intake air temperature (IAT) sensor connector.