Notice: The oxygen sensor uses a permanently attached pigtail and connector. Do not remove the pigtail from the oxygen sensor. Damage to or removal of the pigtail connector could affect proper operation of the oxygen sensor.

Important: Take care when handling the Oxygen Sensor (O2S 1). The in-line electrical connector and louvered end must be kept free of grease, dirt or other contaminants. Avoid using cleaning solvents of any type. DO NOT drop or roughly handle the O2S 1.

Important: The O2S 1 may be difficult to remove when the engine temperature is below 48°C (120°F).

Notice: The use of excessive force may damage the threads in the exhaust manifold/pipe.

1. Turn OFF the ignition switch.
2. Disconnect the Oxygen Sensor 1 electrical connector (2).
3. Carefully remove the oxygen sensor (1).

Important: A special anti-seize compound is used on the oxygen 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 an anti-seize compound applied before reinstallation.

1. Coat only the threads of the oxygen sensor (1) with anti-seize compound GM 12377953 or equivalent, if necessary.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

2. Install the Oxygen Sensor (1).

Tighten
Tighten the O2S 1 41 N·m (30 lb ft).

3. Connect the Oxygen Sensor 1 electrical connector (2).