Rear Oxygen Sensor: Removal

Set the vehicle on a lift.
Disconnect the ground cable from battery.

Fig 1: Identifying Battery Ground Cable
Courtesy of SUBARU OF AMERICA, INC.
Lift up the vehicle.
Disconnect the connector from the rear oxygen sensor.
Apply spray-type lubricant 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: Identifying Rear Oxygen Sensor

Courtesy of SUBARU OF AMERICA, INC.