Oxygen Sensor: Service and Repair

Heated Oxygen Sensor (HO2S) Electrical Connector:

Heated Oxygen Sensor (HO2S):

REMOVAL PROCEDURE

CAUTION: 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.

CAUTION: Take care when handling the HO2S. 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 or roughly handle the HO2S.

CAUTION: If the heated oxygen sensor pigtail wiring, connector or terminal is damaged, the entire oxygen sensor assembly must be replaced. Do Not attempt to repair the wiring, connector or terminals. In order for the sensor to function properly, it must have provided to it a clean air reference.

CAUTION: This clean air reference is obtained by way of the oxygen sensor signal and heater wires. Any attempt to repair the wires, connectors, or terminals could result in the obstruction of the air reference and degraded sensor performance. The following guidelines should be used when servicing the heated oxygen sensor:

^ Do Not apply contact cleaner or other materials to the sensor or vehicle harness connectors. These materials may get into the sensor causing poor performance.
^ The sensor pigtail and harness wires must not be damaged in such a way that the wires inside are exposed. This could provide a path for foreign materials to enter the sensor and cause performance problems,
^ Neither the sensor or vehicle lead wires should be bent sharply or kinked. Sharp bends, kinks, etc., could block the reference air path through the lead wire.
^ Do Not remove or defeat the oxygen sensor ground wire (where applicable). Vehicles that utilize the ground wired sensor may rely on this ground as the only ground contact to the sensor. Removal of the ground wire will cause poor engine performance.
^ To prevent damage due to water intrusion. be sure that the peripheral seal remains intact on the vehicle harness connector. The engine harness may be repaired using Packard's Crimp and Splice Seals Terminal Repair Kit. Under no circumstances should repairs be soldered since this could result in the air reference being obstructed.

CAUTION: The Heated Oxygen Sensor (HO2S) may be difficult to remove when the engine temperature is below 48°C (120°F). 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.

INSTALLATION PROCEDURE

NOTE: 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 if 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
^ Tighten the sensor to 41 Nm (30 lb. ft.).

3. Install the electrical connector.
4. Connect the negative battery cable.