Knock Sensor: Removal

Remove the collector cover.
Disconnect the ground cable from battery.

Fig 1: Disconnecting Ground Cable From Battery
Courtesy of SUBARU OF AMERICA, INC.
Remove the intercooler. < Ref. to REMOVAL , Intercooler. >
Disconnect the connector from the knock sensor.

Fig 2: Locating Knock Sensor Connector
Courtesy of SUBARU OF AMERICA, INC.
Remove the knock sensor from cylinder block.

Fig 3: Locating Knock Sensor From Cylinder Block
Courtesy of SUBARU OF AMERICA, INC.