GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2009 🢒 Avalanche - 4WD 🢒 Engine 🢒 Engine Exhaust 🢒 Heated Oxygen Sensor Replacement - Bank 1 Sensor 1

Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 1500 Series

Removal Procedure

Caution: Refer to Fastener Caution in the Preface section.


    Object Number: 1704004 Size: SH
  1. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle.
  2. Unbolt the front propeller shaft from the front differential, if equipped with four wheel drive (4WD). Refer to Front Propeller Shaft Replacement.
  3. For vehicles equipped with a 4L60-E/4L70-E automatic transmission perform the following steps, for vehicles equipped with a 6L80-E automatic transmission proceed to step 7.
  4. Remove the connector position assurance (CPA) retainer.
  5. Disconnect the engine wiring harness electrical connector (2) from the HO2S.
  6. Remove the HO2S electrical connector clip (1) from the fuel line clip.

    7. Object Number: 1704002 Size: SH
  7. Remove the CPA retainer (2).
  8. Remove the engine wiring harness electrical connector clip (1) from the fuel line clip.
  9. Disconnect the engine wiring harness electrical connector (3) from the HO2S.

    10. Caution: Refer to Excessive Force and Oxygen Sensor Caution in the Preface section.


    Object Number: 1704008 Size: SH
  10. Remove the HO2S (1 or 2).

Installation Procedure

Note: A special anti-seize compound is used on 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 already 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.

    Caution: Refer to Component Fastener Tightening Caution in the Preface section.


    Object Number: 1704008 Size: SH
  1. If reinstalling the old sensor, coat the threads with anti-seize compound GM P/N 12377953, or equivalent.
  2. Install the HO2S (1 or 2) and tighten to 42 N·m (31 lb ft).

    3. Object Number: 1704004 Size: SH
  3. For vehicles equipped with a 4L60-E/4L70-E automatic transmission perform the following steps, for vehicles equipped with a 6L80-E automatic transmission proceed to step 7.
  4. Install the HO2S electrical connector clip (1) to the fuel line clip.
  5. Connect the engine wiring harness electrical connector (2) to the HO2S.
  6. Install the CPA retainer.

    7. Object Number: 1704002 Size: SH
  7. Connect the engine wiring harness electrical connector (3) to the HO2S.
  8. Install the engine wiring harness electrical connector clip (1) to the fuel line clip.
  9. Install the CPA retainer (2).
  10. Install the front propeller shaft to the front differential, if equipped with 4WD. Refer to Front Propeller Shaft Replacement.
  11. Lower the vehicle.

Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 2500 Series

Removal Procedure

Caution: Refer to Heated Oxygen and Oxygen Sensor Caution in the Preface section.


    Object Number: 1704010 Size: SH
  1. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle.
  2. Unbolt the front propeller shaft from the front differential, if equipped with four wheel drive (4WD). Refer to Front Propeller Shaft Replacement.
  3. Remove the connector position assurance (CPA) retainer (2).
  4. Disconnect the HO2S electrical connector from the engine wiring harness electrical connector (3).

    5. Caution: Refer to Excessive Force and Oxygen Sensor Caution in the Preface section.


    Object Number: 1704012 Size: SH
  5. Remove the HO2S (1).

Installation Procedure

Note: A special anti-seize compound is used on 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 already 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.

    Caution: Refer to Component Fastener Tightening Caution in the Preface section.


    Object Number: 1704012 Size: SH
  1. If reinstalling the old sensor, coat the threads with anti-seize compound GM P/N 12377953, or equivalent.
  2. Install the HO2S (1) and tighten to 42 N·m (31 lb ft).

    3. Object Number: 1704010 Size: SH
  3. Connect the HO2S electrical connector to the engine wiring harness electrical connector (3).
  4. Install the CPA retainer (2).
  5. Install the front propeller shaft to the front differential, if equipped with 4WD. Refer to Front Propeller Shaft Replacement.
  6. Lower the vehicle.