Rear Oxygen Sensor: Removal

Disconnect the ground terminal from battery sensor. < Ref. to BATTERY , NOTE, Repair Contents. >
Lift up the vehicle.
Remove the under cover. < Ref. to REMOVAL , Front Under Cover. >
Disconnect the rear oxygen sensor connector.

Fig 1: Identifying Front (A/F) And Rear Oxygen Sensor Connector
Courtesy of SUBARU OF AMERICA, INC.
Remove the front mud guard RH. < Ref. to REMOVAL , Mud Guard. >
Apply spray-type lubricant (004301003) or equivalent to the threaded portion of rear oxygen sensor, and leave it for one minute or more.
Remove the rear oxygen sensor.
CAUTION: When removing the rear oxygen sensor, wait until exhaust pipe cools, otherwise it will damage the exhaust pipe.

Fig 2: Locating Rear Oxygen Sensor Bolt
Courtesy of SUBARU OF AMERICA, INC.