Rear Oxygen Sensor - Subaru 2009 IMPREZA Service Manual

16.Rear Oxygen Sensor

A: REMOVAL
1) Set the vehicle on a lift.
2) Disconnect the ground cable from battery.
3) Remove the air intake duct. <Ref. to IN(H4SO)-
8, REMOVAL, Air Intake Duct.>
4) Remove the clip fastening the harness and dis-
connect the rear oxygen sensor connector.
(B)
(C)
(A) Front oxygen (A/F) sensor connector
(B) Rear oxygen sensor connector
(C) Clip
5) Lift up the vehicle.
6) Remove the under cover.
7) Apply spray-type lubricant to the threaded por-
tion of rear oxygen sensor, and leave it for one
minute or more.
Rear Oxygen Sensor
8) Remove the rear oxygen sensor.
CAUTION:
When removing the rear oxygen sensor, wait
until exhaust pipe cools, otherwise it will dam-
age the exhaust pipe.
IN-00203
B: INSTALLATION
(A) CAUTION:
If lubricant is spilt onto the exhaust pipe, wipe it
off completely with cloth to avoid emission of
smoke or causing a fire.
1) Before installing rear oxygen sensor, apply the
anti-seize compound only to the threaded portion of
rear oxygen sensor to make the next removal eas-
ier.
CAUTION:
EX-02350
Never apply anti-seize compound to the protec-
tor of rear oxygen sensor.
Anti-seize compound:
NEVER-SEEZ NSN, JET LUBE SS-30 or
equivalent
2) Install the rear oxygen sensor.
Tightening torque:
21 N·m (2.1 kgf-m, 15.5 ft-lb)
FU(H4SO)-43
FUEL INJECTION (FUEL SYSTEMS)
(B)
(A)
(A) Front oxygen (A/F) sensor
(B) Rear oxygen sensor
(B)
(A)
(A) Front oxygen (A/F) sensor
(B) Rear oxygen sensor
FU-02735
FU-02735