GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2005 🢒 LaCrosse 🢒 Body 🢒 Wiring Systems 🢒 Heated Oxygen Sensor Replacement - Sensor 1

Tools Required

J 39194 Oxygen Sensor Wrench

Notice: The Heated Oxygen Sensor (HO2S) and the Oxygen Sensor use a permanently attached pigtail and connector. Do not remove this pigtail from the Heated Oxygen Sensor. Damage or the removal of the pigtail or the connector could affect the proper operation of the sensor.

Take care when handling the HO2S and the O2S. Keep the in-line electrical connector and the louvered end free of grease, dirt, or other contaminants. Also avoid using cleaning solvents of any type. Do not drop the HO2S or the O2S. Do not roughly handle the HO2S or the O2S.

Removal Procedure

    Object Number: 911055 Size: SH

    Notice: The oxygen sensor may be difficult to remove when the engine temperature is below 48°C (120°F). Excessive force may damage threads in the exhaust manifold or the exhaust pipe.

  1. Remove the fuel injector sight shield. Refer to Fuel Injector Sight Shield Replacement .
  2. Remove the heated oxygen sensor (HO2S) retaining clip.
  3. Disconnect the HO2S electrical connector (1).
  4. Remove the HO2S electrical connector (1) from the fuel injector sight shield bracket.

    5. Important: Remove the oxygen sensors with the engine temperature above 48°C (120°F). Otherwise the oxygen sensors may be difficult to remove.

  5. Use the J 39194 to remove the HO2S (2) from the right exhaust manifold.

Installation Procedure

    Notice: Refer to Heated Oxygen Sensor Resistance Learn Reset Notice in the Preface section.

    Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 911055 Size: SH

    Important: A special anti-seize compound is used on the oxygen sensors (1) threads. New service sensors should already have the compound applied to the threads. Coat the threads of a reused sensor with anti-seize compound GM P/N 12377953 or equivalent.

  1. Install the HO2S (2) to the right exhaust manifold.

    2. Tighten
    Use the J 39194 to tighten the HO2S to 42 N·m (31 lb ft).

  2. Install the HO2S electrical connector (1) to the fuel injector sight shield bracket.
  3. Connect the HO2S electrical connector (1).
  4. Install the HO2S retaining clip.
  5. Install the fuel injector sight shield. Refer to Fuel Injector Sight Shield Replacement .