GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

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

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


    Object Number: 1836987  Size: SH
  1. Remove the exhaust manifold heat shield. Refer to Exhaust Manifold Heat Shield Replacement - Left Side .
  2. Remove the oil level indicator. Refer to Oil Level Indicator and Tube Replacement .
  3. Remove the catalytic converter. Refer to Catalytic Converter Replacement - Left Side .
  4. Remove the exhaust manifold bolts (1).
  5. Important: Do not reuse the gasket.

  6. Remove the exhaust manifold and gasket. Discard the gasket.

  7. Object Number: 1858130  Size: SH
  8. Remove the heated oxygen sensor (1) from the exhaust manifold.

Installation Procedure

Important: A special anti-seize compound is used in the HO2S threads. The compound consists of liquid graphite and glass beads. The graphite tends to burn away, but the glass beads remain, making the sensor easier to remove. New, or service replacement sensors have the compound applied to the threads. If the sensor is removed from an exhaust component and if for any reason the sensor is to be reinstalled, the threads must have anti-seize compound applied before the reinstallation.


    Object Number: 1858130  Size: SH
  1. If reinstalling the old sensor, coat the threads with anti-seize compound GM P/N 12377953, or equivalent.
  2. Notice: Refer to Fastener Notice in the Preface section.

  3. Install the HO2S (1) to the exhaust manifold.
  4. Tighten
    Tighten the sensor to 42 N·m (31 lb ft).


    Object Number: 1836987  Size: SH
  5. Install one exhaust manifold bolt (1) to the exhaust manifold.
  6. Install the NEW exhaust manifold gasket onto the exhaust manifold and bolt.
  7. Install the exhaust manifold (with gasket) to the cylinder head and the catalytic converter.
  8. Install the remaining exhaust manifold bolts.
  9. Tighten
    Tighten the bolts to 20 N·m (15 lb ft).

  10. Install the catalytic converter. Refer to Catalytic Converter Replacement - Left Side .
  11. Install the oil level indicator. Refer to Oil Level Indicator and Tube Replacement .
  12. Install the exhaust manifold heat shield. Refer to Exhaust Manifold Heat Shield Replacement - Left Side .