Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Manual — part 89

EX(STI)-4

General Description

EXHAUST

• 5 door model

(1)

Gasket

(11) Rear exhaust pipe

Tightening torque: N·m (kgf-m, ft-lb)

(2)

Front catalytic converter

(12) Chamber

T1: 13 (1.3, 9.6)

(3)

Center exhaust pipe (front)

(13) Cushion rubber

T2: 18 (1.8, 13.3)

(4)

Center exhaust pipe (rear)

(14) Spring

T3: 23 (2.3, 17.0)

(5)

Gasket

(15) Bolt

T4: 30 (3.1, 22.1)

(6)

Center exhaust pipe upper cover

(16) Gasket

T5: 35 (3.6, 25.8)

(7)

Clamp

(17) Self-locking nut

T6: 40 (4.1, 29.5)

(8)

Rear oxygen sensor

(18) Muffler

T7: 42.5 (4.3, 31.3)

(9)

Rear catalytic converter

(19) Hanger bracket (5MT model)

T8: 48 (4.9, 35.4)

(10) Gasket

(20) Hanger bracket (6MT model)

T9: <Ref. to FU(STI)-56, INSTALLA-

TION, Rear Oxygen Sensor.>
<Ref. to FU(w/o STI)-55,
INSTALLATION, Rear Oxygen
Sensor.>

EX-02728

(10)

(15)

(14)

(12)

(13)

(18)

(16)

T8

(11)

(17)

(13)

(13)

A

(9)

T5

T7

T2

(6)

(4)

(8)

(7)

T2

T1

A

T9

(5)

T4

T7

T7

(1)

(2)

(3)

T3

(20)

T6

(19)

EX(STI)-5

General Description

EXHAUST

B: CAUTION

• Prior to starting work, pay special attention to the following:

1. Always wear work clothes, a work cap, and protective shoes. Additionally, wear a helmet, protective

goggles, etc. if necessary.
2. Protect the vehicle using a seat cover, fender cover, etc.
3. Prepare the service tools, clean cloth, containers to catch grease and oil, etc.

• Vehicle components are extremely hot immediately after driving. Be wary of receiving burns from heated

parts.

• When performing a repair, identify the cause of trouble and avoid unnecessary removal, disassembly and

replacement.

• Before disconnecting connectors of sensors or units, be sure to disconnect the ground cable from battery.

• Always use the jack-up point when the shop jacks or rigid racks are used to support the vehicle.

• Remove contamination including dirt and corrosion before removal, installation, disassembly or assembly.

• Keep the removed parts in order and protect them from dust and dirt.

• All removed parts, if to be reused, should be reinstalled in the original positions with attention to the correct

directions, etc.

• Bolts, nuts and washers should be replaced with new parts as required.

• Be sure to tighten the fasteners including bolts and nuts to the specified torque.

• If any grease adheres to the exhaust pipe, wipe it off. Otherwise a fire may happen.

EX(STI)-6

Front Exhaust Pipe

EXHAUST

2. Front Exhaust Pipe

A: REMOVAL

CAUTION:

Vehicle components are extremely hot after

driving. Be wary of receiving burns from heated

parts.

1) Disconnect the ground cable from battery.

2) Lift up the vehicle.

3) Remove the under cover. <Ref. to EI-28, RE-

MOVAL, Front Under Cover.>

4) Remove the front oxygen (A/F) sensor. <Ref. to

FU(STI)-54, REMOVAL, Front Oxygen (A/F) Sen-

sor.> <Ref. to FU(w/o STI)-53, REMOVAL, Front

Oxygen (A/F) Sensor.>

5) Remove the exhaust manifold RH lower cover

and exhaust manifold LH cover.

6) Remove the bolts and nuts which hold joint pipe

onto exhaust manifold RH.

7) While holding the front exhaust pipe with one

hand, remove the nuts which hold the exhaust

manifold to the cylinder head exhaust port and re-

move the front exhaust pipe.

B: INSTALLATION

1) Install the front exhaust pipe.
NOTE:

Use a new gasket.
Tightening torque:

40 N·m (4.1 kgf-m, 29.5 ft-lb)

IN-00203

EX-02253

EX-00018

EX-02254

EX-00005

EX-02254

EX-00005

EX(STI)-7

Front Exhaust Pipe

EXHAUST

2) Install the joint pipe to the exhaust manifold RH.
NOTE:

Use a new gasket.
Tightening torque:

42.5 N·m (4.3 kgf-m, 31.3 ft-lb)

3) Install the exhaust manifold RH lower cover and

exhaust manifold LH cover.
Tightening torque:

19 N·m (1.9 kgf-m, 14.0 ft-lb)

4) Install the front oxygen (A/F) sensor. <Ref. to

FU(STI)-54, INSTALLATION, Front Oxygen (A/F)

Sensor.> <Ref. to FU(w/o STI)-53, INSTALLA-

TION, Front Oxygen (A/F) Sensor.>

5) Install the under cover. <Ref. to EI-28, INSTAL-

LATION, Front Under Cover.>

6) Lower the vehicle.

7) Connect the battery ground terminal.

C: DISASSEMBLY

1) Remove the exhaust manifold RH upper cover.

2) Remove the exhaust manifold RH and the ex-

haust manifold LH from the front exhaust pipe.

D: ASSEMBLY

1) Install the exhaust manifold RH and the exhaust

manifold LH to the front exhaust pipe.
NOTE:

Use a new gasket.
Tightening torque:

42.5 N·m (4.3 kgf-m, 31.3 ft-lb)

2) Install the exhaust manifold RH upper cover.
Tightening torque:

19 N·m (1.9 kgf-m, 14.0 ft-lb)

E: INSPECTION

1) Check the connections and welds for exhaust

leaks.

2) Make sure there are no holes or rusting.

EX-00018

EX-02253

IN-00203

(A) Front exhaust pipe
(B) Exhaust manifold RH

(C) Exhaust manifold LH
(D) Gasket

(E) Gasket

(A) Front exhaust pipe
(B) Exhaust manifold RH

(C) Exhaust manifold LH
(D) Gasket

(E) Gasket

EX-02729

(D)

(A)

(B)

(C)

(E)

EX-02730

(D)

(A)

(B)

(C)

(E)