Oxygen Sensors: Notes
WARNING: This page is about a different car, the 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Silverado, and 2003 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION:
Do not repair wiring, connector or terminals on oxygen sensor. Replace oxygen sensor if pigtail wiring, connector or terminal is damaged. Oxygen sensors are equipped with a permanent pigtail which must remain intact when removing sensor. Ensure oxygen sensor is free of contaminants. DO NOT use cleaning solvents of any type. Oxygen sensor may be difficult to remove when engine temperature is less than 120°F (48°C). Excessive removal force may damage threads in exhaust pipe.
NOTE:
Front Heated Oxygen Sensors (HO2S1/1 and HO2S2/1) are located in the exhaust pipes, below the respective exhaust manifold. See Figure. Rear Heated Oxygen Sensors (HO2S1/2 and HO2S2/2) are mounted in the exhaust pipes, behind the respective catalytic converter. On some 8.1L models, it may be necessary to lower the exhaust system to gain sufficient access to a HO2S and/or HO2S harness connector.