Removal (3.1L & 3.4L)
WARNING: This page is about a different car, the 2003 Pontiac Grand Prix, 2003 Chevrolet Monte Carlo, 2003 Chevrolet Impala, 2003 Buick Regal, and 2003 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.
Turn OFF the ignition. HO2S 1 is located in exhaust manifold. Disconnect the heated oxygen sensor electrical connector. Remove the heated oxygen sensor. See Figure. HO2S 2 is located behind catalytic converter. See Figure. If removing HO2S 2, raise and support vehicle. On all sensors, disconnect the HO2S harness connector. Using Heated Oxygen Sensor Wrench (J-39194-B), remove the HO2S.