Oxygen Sensor: Service and Repair

Oxygen Sensor:

SPECIAL TOOL REQUIRED (or equivalent)
^ J-38756, Oxygen sensor wrench.

CAUTIONS:
^ The Oxygen (O2) sensor uses a permanently attached pigtail and connector. This pigtail should not be removed from the oxygen sensor. Damage or removal of the pigtail or connector could affect proper operation of the oxygen sensor.

^ Take care when handling the O2 sensor. 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 O2 sensor.

^ The O2 sensor 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.

REMOVE OR DISCONNECT
1. Negative battery cable.
2. The O2 sensor is removed from underneath the vehicle.
3. Converter intermediate exhaust assembly.
4. Electrical connector.
5. O2 sensor with J-38756. The engine must be cool and the sensor must be removed by hand.
6. Carefully back out the O2 sensor using J-38756.

NOTE: A special anti-seize compound is used on the O2 sensor threads. The compound consists of a liquid graphite and glass beads. The graphite will burn away, but the glass beads will remain, making the sensor easier to remove. New or service 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.

INSTALL OR CONNECT
1. Coat threads of O2 sensor with anti-seize compound GM P/N 5613695, or equivalent if necessary.
2. O2 sensor and torque to 42 Nm (31 lb ft).
3. Electrical connector.
4. Converter intermediate exhaust assembly.
5. Lower vehicle.
6. Negative battery cable.
7. Before starting engine, follow the "Idle Learn Procedure" as follows:
a. Install Tech 1 "Scan" tool.
b. Ignition "ON", engine "OFF".
c. Transaxle in park or neutral.
d. Select "IAC SYSTEM," then "IDLE LEARN" in the "MISC TEST" mode.
e. Proceed with idle learn as directed. This procedure allows the ECM memory to be updated with the correct IAC valve pintle position for the vehicle, and provides for a stable idle speed.