Removal (2.2L)

WARNING: This page is about a different car, the 2003 Pontiac Grand Am and 2003 Oldsmobile Alero. However, it is still accessible from the selected car via links, so may be relevant.

Knock Sensor (KS) is located on side of cylinder block behind starter. See Fig 1 . Disconnect the negative battery cable.
Raise and support the vehicle.
Disconnect the electrical connectors from the starter.
Remove the starter bolts. Remove the starter.
Disconnect the KS harness connector.
Remove the KS retaining bolt.
Remove the KS.

Fig 1: Locating Knock Sensor (2.2L)

Courtesy of GENERAL MOTORS CORP.