Rear Oxygen Sensor: Removal

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

Fig 1: Disconnecting Ground Cable From Battery
Courtesy of SUBARU OF AMERICA, INC.
Lift-up the vehicle.
Disconnect the connector from rear oxygen sensor.
- LH side
  
  Fig 2: Disconnecting Connector From Rear Oxygen Sensor (LH)
  Courtesy of SUBARU OF AMERICA, INC.
- RH side
Fig 3: Disconnecting Connector From Rear Oxygen Sensor (RH)
Courtesy of SUBARU OF AMERICA, INC.
Remove the clip holding harness.
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.

LH side

Fig 4: Removing Rear Oxygen Sensor (LH)
Courtesy of SUBARU OF AMERICA, INC.
RH side

Fig 5: Removing Rear Oxygen Sensor (RH)
Courtesy of SUBARU OF AMERICA, INC.