GM 91177409
Oxygen Sensor

When servicing the heated Oxygen Sensor (HO2S) 1 handle it cautiously to prevent dropping and maintain the in-line electrical connector and louvered end free from contaminants with no usage of cleaning solvents allowed. The operation of the sensor will be affected if you remove its pigtail from the ho2s and Oxygen Sensor (O2S). Also replace the Oxygen Sensor when you discover any wiring or connector or terminal damage. The application of contact cleaner on sensor or vehicle harness connectors should be avoided and both the sensor pigtail and harness wires need to remain covered and free of any kinks since exposure could result in performance failures. Maintaining the Oxygen Sensor ground wire connection is essential when possible because the wire provides essential grounding for the device and you should verify that the peripheral seal around the vehicle harness connector remains intact to block water intrusion. The operation to remove ho2s 1 requires engine temperature below 48°c (120°F) because high temperatures make the sensor difficult to uninstall. First disconnect the electrical connector from ho2s 1 and then take the sensor out of the Exhaust Manifold. Before installing the new ho2s 1 sensor with its pre-applied anti-seize coating users need to preserve this coating; when replacing an existing sensor use anti-seize compound on the threads before installing. Place the ho2s 1 onto the Exhaust Manifold while tightening it to 40-50 n.m (29-36 lb ft) and connect the ho2s 1 electrical connector.

Reconnect the HO2S 1 electrical connector and the negative battery cable.

Avoid applying contact cleaner to the sensor or vehicle harness connectors, damaging the sensor pigtail and harness wires, or creating sharp bends or kinks in the lead wires.