Oxygen Sensor: Service and Repair

NOTE
The Heated Oxygen Sensor (HO2S) uses a permanently attached pigtail and connector. This pigtail should not be removed from the Heated Oxygen Sensor (HO2S). Damage or removal of the pigtail or connector could affect proper operation of the oxygen sensor.

Take care when handling the Heated Oxygen Sensor (HO2S). The in-line electrical connector and louvered end must be kept free of grease, dirt, or other contaminants. Also, avoid using cleaning solvents of any type. Do not drop or roughly handle the heated oxygen sensor.

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. 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 oxygen sensor performance.

CAUTION
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. Also, 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 also cause poor engine performance.
^ The Heated Oxygen Sensor (HO2S) may be difficult to remove, when engine temperature is below 48°C (120°F). Excessive force may damage threads in exhaust manifold or exhaust pipe.

NOTE The engine harness may be repaired using Packard's Crimp and Splice Seals Terminal Repair Kit J 38125-A. Under no circumstances should repairs be soldered since this could result in the air reference being obstructed.

Remove or Disconnect
1. Negative battery cable.
2. Electrical connector releasing locking tab.
3. Carefully back out oxygen sensor.

Install or Connect

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 will tend to burn away, but the glass beads will remain, making the sensor easier to remove.
New, or service replacement sensors will already have the compound applied to the threads. If a 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 reinstallation.

1. Coat threads of heated oxygen sensor with anti-seize compound (GM PIN 5613695 or equivalent), if necessary.
2. Sensor, and torque to 41 Nm (30 ib. ft.).
3. Electrical connector.
4. Negative battery cable.