Knock Sensor: Removal

Disconnect the ground cable from battery. < Ref. to BATTERY , NOTE, Note.>
NOTE: For the 12 volt engine restart battery, disconnect the ground terminal from 12V engine restart battery sensor.
Remove the collector cover.
1. Pull up the two points at the front of collector cover (A).
2. Pull up the two points at the rear of collector cover (B) while moving them rearward.
  NOTE: Be careful not to contact the fuel delivery tube when moving the collector cover rearward.
  
  Fig 1: Removing Front/Rear Of Collector Cover
  Courtesy of SUBARU OF AMERICA, INC.
Remove the throttle body. < Ref. to REMOVAL , Throttle Body.>
Disconnect the connector (A) from the knock sensor, and remove the knock sensor from the cylinder block.

Fig 2: Locating Knock Sensor Connector Mounting Bolts
Courtesy of SUBARU OF AMERICA, INC.