Subaru Legacy (2005 year). Manual - part 168

FU(H4SO 2.5)-35

FUEL INJECTION (FUEL SYSTEMS)

Front Oxygen (A/F) Sensor

17.Front Oxygen (A/F) Sensor

A: REMOVAL

1) Disconnect the ground cable from battery.

2) Remove the air intake duct. <Ref. to IN(H4SO
2.0)-8, REMOVAL, Air Intake Duct.>
3) Remove the connector of front oxygen (A/F)
sensor.

4) Remove the clip which holds harness.
5) Lift-up the vehicle.
6) Remove the under cover.
7) Apply spray-type lubricant to the threaded por-
tion of front oxygen (A/F) sensor, and leave it for
one minute or more.
8) Remove the front oxygen (A/F) sensor.

CAUTION:
When removing the front oxygen (A/F) sensor, 
wait until exhaust pipe cools, otherwise it will 
damage the exhaust pipe.

B: INSTALLATION

1) Before installing front oxygen (A/F) sensor, ap-
ply anti-seize compound only to the threaded por-
tion of front oxygen (A/F) sensor to make the next
removal easier.

Anti-seize compound:

SS-30 JET LUBE

CAUTION:
Never apply anti-seize compound to the protec-
tor of front oxygen (A/F) sensor.
2) Install the front oxygen (A/F) sensor.

Tightening torque:

21 N

⋅

m (2.1 kgf-m, 15.2 ft-lb)

3) Install the under cover.
4) Lower the vehicle.
5) Hold the harness with clip.
6) Connect the connector of front oxygen (A/F)
sensor.

7) Install the air intake duct. <Ref. to IN(H4SO 2.0)-
8, INSTALLATION, Air Intake Duct.>
8) Connect the ground cable to battery.

IN-00203

ME-00859

FU-01114

FU-01114

ME-00859

IN-00203

FU(H4SO 2.5)-36

FUEL INJECTION (FUEL SYSTEMS)

Rear Oxygen Sensor

18.Rear Oxygen Sensor

A: REMOVAL

1) Disconnect the ground cable from battery.

2) Lift-up the vehicle.
3) Disconnect the connector from rear oxygen sen-
sor.

4) Remove the clip which holds harness.
5) Apply spray-type lubricant to the threaded por-
tion of rear oxygen sensor, and leave it for one
minute or more.
6) 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.

B: INSTALLATION

1) Before installing the rear oxygen sensor, apply
anti-seize compound only to the threaded portion of
the rear oxygen sensor to make the next removal
easier.

Anti-seize compound:

SS-30 JET LUBE

CAUTION:
Never apply anti-seize compound to the protec-
tor of rear oxygen sensor.
2) Install the rear oxygen sensor.

Tightening torque:

21 N

⋅

m (2.1 kgf-m, 15.2 ft-lb)

3) Hold the harness with clip.
4) Connect the connector to rear oxygen sensor.

5) Lower the vehicle.
6) Connect the ground cable to battery.

IN-00203

FU-01116

FU-01117

FU-01117

FU-01116

IN-00203

FU(H4SO 2.5)-37

FUEL INJECTION (FUEL SYSTEMS)

Engine Control Module (ECM)

19.Engine Control Module (ECM)

A: REMOVAL

1) Disconnect the ground cable from battery.

2) Remove the lower inner trim of passenger’s
side.
<Ref. to EI-60, REMOVAL, Lower Inner Trim.>
3) Detach the floor mat of passenger’s seat.
4) Remove the protect cover.

5) Remove the bolt and nut which hold the ECM to
bracket.
6) Remove the clip (A) from bracket.

7) Disconnect the ECM connectors and take out
the ECM.

B: INSTALLATION

Install in the reverse order of removal.

CAUTION:
• When replacing the ECM, be careful not to
use the wrong spec. ECM to avoid any damage
to fuel injection system.
• When replacing the ECM, be careful not to
damage the harnesses and connectors.

Tightening torque:

5 N

⋅

m (0.5 kgf-m, 3.7 ft-lb)

IN-00203

FU-02090

(A)

FU-02488

FU(H4SO 2.5)-38

FUEL INJECTION (FUEL SYSTEMS)

Main Relay

20.Main Relay

A: REMOVAL

1) Disconnect the ground cable from battery.

2) Remove the glove box. <Ref. to EI-51, REMOV-
AL, Glove Box.>
3) Remove the harness cover (A).

4) Disconnect the connector from main relay.

B: INSTALLATION

Install in the reverse order of removal.

IN-00203

FU-02092

(A)

FU-02093