Oxygen Sensors (4.2L): Notes
WARNING: This page is about a different car, the 2003 Oldsmobile Bravada, 2003 GMC Envoy XL, 2003 GMC Envoy, and 2003 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
The Heated Oxygen Sensor 1 (HO2S 1) is located in the exhaust manifold. See Figure. Heated Oxygen Sensor 2 (HO2S 2) is mounted in the exhaust pipe behind the catalytic converter. See Figure. Oxygen sensors are equipped with a permanent pigtail which must remain intact when removing sensor.
CAUTION:
Do not repair wiring, connector or terminals on oxygen sensor. Replace oxygen sensor if pigtail wiring, connector or terminal is damaged.