2009 Chevrolet Silverado 3500 HD Oxygen Sensor

You should not apply contact cleaner or other materials to the sensor or vehicle harness connectors, not damage the sensor pigtail and harness wires in such a way that the wires inside are exposed, not remove or defeat the oxygen sensor ground wire and then ensure that the peripheral seal remains intact on the vehicle harness connector.

The oxygen sensor may be difficult to remove when the engine temperature is below 48°C (120°F). Excessive force may damage threads in the exhaust manifold or the exhaust pipe.

Contamination of the oxygen sensor can result from the use of an inappropriate RTV sealant (not oxygen sensor safe) or excessive engine coolant or oil consumption. You should remove the HO2S and visually inspect the portion of the sensor exposed to the exhaust stream. If contaminated, the portion of the sensor exposed to the exhaust stream will have a white powdery coating. Silicon contamination causes a high but false HO2S signal voltage (rich exhaust indication). The control module will then reduce the amount of fuel delivered to the engine, causing a severe drivability problem. You should eliminate the source of contamination before replacing the oxygen sensor.