Oxygen Sensor: Service and Repair

REMOVAL PROCEDURE

NOTE: 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.

When the engine temperature is below 48°C (12O°F), the Heated Oxygen Sensor (HO2S) may be difficult to remove. Excessive force may damage the threads in the exhaust manifold or the exhaust pipe.

1. Disconnect the negative battery cable.
2. Remove the electrical connector by releasing the locking tab.
3. Carefully back out the heated oxygen sensor you are replacing.
^ HO2S Bank 2 Sensor 1 (1)
^ Catalytic Converter (2)
^ HO2S Bank 1 Sensor 3 (3)
^ HO2S Bank 1 Sensor 2 (4)
^ HO2S Bank 1 Sensor 1 (5)

INSTALLATION PROCEDURE

IMPORTANT: A special anti-seize compound is used on the Heated Oxygen Sensor (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 engine and it for any reason it is to be reinstalled, the threads must have anti-seize compound applied before the reinstallation.

1. Coat the threads of the oxygen sensor with anti-seize compound GM P/N 5613695 or the equivalent if necessary.
2. Install the sensor. Tighten the sensor to 41 Nm (30 lb. ft.).
3. Install the electrical connector.
4. Connect the negative battery cable.