Rear Oxygen Sensor: Removal

Disconnect the ground cable from battery.

Fig 1: Connecting/Disconnecting Battery Ground Cable
Courtesy of SUBARU OF AMERICA, INC.
Lift up the vehicle.
Remove the under cover. Refer to REMOVAL , Front Under Cover.
Disconnect the rear oxygen sensor connector.

Fig 2: Identifying Front, Rear Oxygen (A/F) Sensor Connector And Mounting Clip
Courtesy of SUBARU OF AMERICA, INC.
Apply spray-type lubricant 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 3: Locating Rear Oxygen Sensor
Courtesy of SUBARU OF AMERICA, INC.