Rear Oxygen Sensor: Removal

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

Fig 1: Disconnecting Battery Ground Cable
Courtesy of SUBARU OF AMERICA, INC.
Lift up the vehicle.
Disconnect the connector from rear oxygen sensor.
- LH side
  
  Fig 2: Locating LH Side Rear Oxygen Sensor Connector
  Courtesy of SUBARU OF AMERICA, INC.
- RH side
  
  Fig 3: Locating RH Side Rear Oxygen Sensor Connector
  Courtesy of SUBARU OF AMERICA, INC.
Remove the clip holding the 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: Locating LH Side Rear Oxygen Sensor Connector
  Courtesy of SUBARU OF AMERICA, INC.
- RH side
  
  Fig 5: Locating RH Side Rear Oxygen Sensor Connector
  Courtesy of SUBARU OF AMERICA, INC.