oxygen SUBARU FORESTER 2004 Service User Guide

EX(H4SO)-5
EXHAUST
General Description
(1) Front exhaust pipe upper cover
CTR(15) Rear exhaust upper cover (31) Front catalytic converter upper
cover
(16) Rear exhaust lower cover
(2) Front exhaust pipe lower cover
CTR(17) Rear catalytic lower converter
cover(32) Front oxygen (A/F) sensor
(33) Rear oxygen sensor
(3) Clamp (18) Clamp (34) Clamp
(4) Front exhaust pipe upper cover LH (19) Cushion rubber
(5) Front exhaust pipe lower cover LH (20) Rear exhaust pipeTightening torque: N
⋅m (kgf-m, ft-lb)
(6) Front exhaust pipe (21) GasketT1: 8 (0.8, 5.8)
(7) Front exhaust pipe lower cover RH (22) Self-locking nutT2: 13 (1.3, 9.4)
(8) Front exhaust pipe upper cover
RH(23) MufflerT3: 18 (1.8, 13.0)
(24) ProtectorT4: 21 (2.1, 15.2)
(9) Gasket (25) GasketT5: 30 (3.1, 22.4)
(10) Gasket (26) Front catalytic converterT6: 35 (3.6, 26.0)
(11) Spring (27) Center exhaust lower coverT7: 48 (4.9, 35.4)
(12) Chamber (28) Center exhaust upper cover
(13) Rear catalytic converter (29) Center exhaust pipe
(14) Rear catalytic converter upper
cover(30) Front catalytic converter lower
cover

EX(H4SO)-7
EXHAUST
Front Exhaust Pipe
2. Front Exhaust Pipe
A: REMOVAL
1) Disconnect the ground cable from battery.
2) Disconnect the front oxygen (A/F) sensor con-
nector.
3) Disconnect the rear oxygen sensor connector.4) Lift-up the vehicle.
5) Separate the front and center exhaust pipe as-
sembly from rear exhaust pipe.
CAUTION:
Be careful, the exhaust pipe is hot.
6) Remove the under cover.
7) Remove the nuts which hold front exhaust pipe
onto cylinder heads.
8) Remove the bolt which installs front and center
exhaust pipe assembly to hanger bracket.
FU-00009
EX-00029
EX-00030
EX-00037
EC-00009
EX-00038

EX(H4SO)-8
EXHAUST
Front Exhaust Pipe
9) Remove the front and center exhaust pipe as-
sembly from vehicle.
CAUTION:
 Be careful not to let the front and center ex-
haust pipe assembly fall off when removing as
it is quite heavy.
 After removing the front and center exhaust
pipe assembly, do not apply excessive pulling
force on the rear exhaust pipe.
10) Separate the front exhaust pipe from center ex-
haust pipe.
11) Remove the front oxygen (A/F) sensor and the
rear oxygen sensor. MOVAL, Front Oxygen (A/F) Sensor.> FU(H4SO)-42, REMOVAL, Rear Oxygen Sensor.>
B: INSTALLATION
1) Install the front oxygen (A/F) sensor and the rear
oxygen sensor. TION, Front Oxygen (A/F) Sensor.> FU(H4SO)-42, INSTALLATION, Rear Oxygen
Sensor.>
2) Install the front exhaust pipe to center exhaust
pipe.
NOTE:
Replace the gaskets with new ones.
Tightening torque:
30 N
⋅m (3.1 kgf-m, 22.4 ft-lb)
3) Install the front and center exhaust pipe assem-
bly to vehicle.4) Temporarily tighten the bolt which installs front
and center exhaust pipe assembly to hanger brack-
et.
5) Tighten the nuts which hold front exhaust pipe
onto cylinder heads.
Tightening torque:
30 N
⋅m (3.1 kgf-m, 22.4 ft-lb)
6) Install the under cover.
7) Tighten the bolts which install front and center
exhaust pipe assembly to rear exhaust pipe.
Tightening torque:
18 N
⋅m (1.8 kgf-m, 13.0 ft-lb)
EC-00011
EC-00011
EX-00038
EC-00009
EX-00037

EX(H4SO)-9
EXHAUST
Front Exhaust Pipe
8) Tighten the bolt which holds front and center ex-
haust pipe assembly to hanger bracket.
Tightening torque:
35 N
⋅m (3.6 kgf-m, 26.0 ft-lb)
9) Lower the vehicle.
10) Connect the rear oxygen sensor connector.
11) Connect the front oxygen (A/F) sensor connec-
tor.
12) Connect the battery ground cable to battery.
C: INSPECTION
1) Make sure there are no exhaust leaks from con-
nections and welds.
2) Make sure there are no holes or rusting.
EX-00038
EX-00030
EX-00029
FU-00009

EN(H4SO)-13
ENGINE (DIAGNOSTIC)
Electrical Component Location
EN-00162
(2)
(3) (1)
(4)
(1) Front oxygen (A/F) sensor (3) Front catalytic converter (4) Rear catalytic converter
(2) Rear oxygen sensor
EN-00014
(1)
EN-00163 (2)
EN-00016
(3)
EN-00164 (4)

EN(H4SO)-21
ENGINE (DIAGNOSTIC)
Engine Control Module (ECM) I/O Signal
5. Engine Control Module (ECM) I/O Signal
A: ELECTRICAL SPECIFICATION
DESCRIPTION Connector No. Terminal No.Signal (V)
NOTE
Ignition SW ON
(engine OFF)Engine ON
(Idling)
Crank-
shaft posi-
tion sensorSignal (+) B135 6 0−7 — +7 Sensor output waveform
Signal (−) B135 17 0 0 —
Shield B135 28 0 0 —
Camshaft
position
sensorSignal (+) B135 7 0−7 — +7 Sensor output waveform
Signal (−) B135 18 0 0 —
Shield B135 28 0 0 —
Throttle
position
sensorSignal B135 13Fully closed: 0.2 — 1.0
Fully opened: 4.2 — 4.7—
Pow er
supplyB135 3 5 5 —
GND
(sensor)B135 19 0 0 —
Rear oxy-
gen sensorSignal B135 14 0 0 — 0.9 —
Shield B137 15 0 0 —
GND
(sensor)B135 19 0 0 —
Fr o nt ox y-
gen (A/F)
sensor
heaterSignal 1 B136 13 0 — 1.0 0 — 1.0 —
Signal 2 B136 22 0 — 1.0 0 — 1.0 —
Rear oxygen sensor
heater signalB136 4 0 — 1.0 0 — 1.0 —
Engine
coolant
tempera-
ture sen-
sorSignal B135 12 1.0 — 1.4 1.0 — 1.4 After engine is warmed-up.
GND
(sensor)B135 19 0 0 After engine is warmed-up.
Vehicle speed signal B137 10 0 or 5 0 or 5“5” and “0” are repeatedly dis-
played when vehicle is driven.
Starter switch B136 20 0 0 Cranking: 8 — 14
EN-00258
B135B134
B137B136
1234567891011121314151617181920
1 2 3 4
5
6
7 8
910 11 12 13 14 15
16
17 18
19 20 21
22 23
24
25 26 27
28
29
30 31 32
33
34 351 2 3
4
5
6
7
8 910 11
12
13 14
15 16 17
18 19
20
21 22
23 24 25
26 27
28
1 2
3
4 5 6
7
8
910
11 12
13 14 15 16
17
18 19 20 21 22 23
24
25 26
To
To
To To

EN(H4SO)-23
ENGINE (DIAGNOSTIC)
Engine Control Module (ECM) I/O Signal
Small light switch B137 20ON: 0
OFF: 10 — 13ON: 0
OFF: 12 — 14—
Blower fan switch B137 13ON: 0
OFF: 10 — 13ON: 0
OFF: 12 — 14—
Rear defogger switch B137 4ON: 0
OFF: 10 — 13ON: 0
OFF: 12 — 14—
Front oxygen (A/F) sen-
sor signal 1B136 13 — 2.05 — 2.25 —
Front oxygen (A/F) sen-
sor signal 2B136 22 — 1.75 — 1.95 —
Manifold absolute pres-
sure sensorB135 15 4.0 — 4.8 1.1 — 1.9 —
Intake air temperature
sensorB137 6 3.15 — 3.33 3.15 — 3.33Intake air temperature: 25°C
(75°F)
SSM/GST communica-
tion lineB137 16Less than 1←→
More than 4Less than 1←→
More than 4—
GND (sensor) B136 19 0 0 —
GND (injector) B134 35 0 0 —
GND (ignition system) B136 26 0 0 —
GND (power supply) B134 7 0 0 —
GND (control system)B137 14 0 0 —
B135 21 0 0 —
GND (oxygen sensor
heater 1)B136 5 0 0 —
GND (oxygen sensor
heater 2)B136 16 0 0 — DESCRIPTION Connector No. Terminal No.Signal (V)
NOTE
Ignition SW ON
(engine OFF)Engine ON
(Idling)

EN(H4SO)-27
ENGINE (DIAGNOSTIC)
OBD-II General Scan Tool
9. OBD-II General Scan Tool
A: OPERATION
1. HOW TO USE OBD-II GENERAL SCAN
TOOL
1) Prepare a general scan tool (OBD-II general
scan tool) required by SAE J1978.
2) Connect the OBD-II general scan tool to its data
link connector in the lower portion of the instrument
panel (on the driver’s side).3) Using the OBD-II general scan tool, call up the
DTC and freeze frame data.
OBD-II general scan tool functions consist of:
(1) MODE $01: Current powertrain diagnostic
data
(2) MODE $02: Powertrain freeze frame data
(3) MODE $03: Emission-related powertrain
DTC
(4) MODE $04: Clear/Reset emission-related
diagnostic information
Read out data according to repair procedures. (For
detailed operation procedures, refer to the OBD-II
General Scan Tool Operation Manual.)
NOTE:
For details concerning DTCs, refer to the List of Di-
agnostic Trouble Code (DTC). 72, List of Diagnostic Trouble Code (DTC).>
2. MODE $01 (CURRENT POWERTRAIN DIAGNOSTIC DATA)
Refers to data denoting the current operating condition of analog input/output, digital input/output and/or the
powertrain system.
A list of the support data and PID (Parameter Identification) codes are shown in the following table.
NOTE:
Refer to OBD-II general scan tool manufacturer’s instruction manual to access generic OBD-II PIDs (MODE
$01).
ME-00325
PID Data Unit of measure
01 Number of emission-related powertrain DTC and malfunction indicator light status ON/OFF
03 Fuel system control status—
04 Calculated engine load value%
05 Engine coolant temperature°C
06 Short term fuel trim%
07 Long term fuel trim%
0B Intake manifold absolute pressure kPa
0C Engine speedrpm
0D Vehicle speedkm/h
0E Ignition timing advance°
10 Air flow rate of manifold absolute pressure sensor g/sec
11 Throttle valve opening angle%
13 Check whether oxygen sensor is installed. —
14Oxygen sensor output voltage and short term fuel trim — bank 1 associated with oxygen sen-
sorV and%
15Oxygen sensor output voltage and short term fuel trim — bank 2 associated with oxygen sen-
sorV and %
1C On-board diagnostic system—

EN(H4SO)-30
ENGINE (DIAGNOSTIC)
Subaru Select Monitor
4. READ CURRENT DATA FOR ENGINE. (NORMAL MODE)
1) On the «Main Menu» display screen, select the {Each System Check} and press the [YES] key.
2) On the «System Selection Menu» display screen, select the {Engine} and press the [YES] key.
3) Press the [YES] key after the information of engine type was displayed.
4) On the «Engine Diagnosis» display screen, select the {Current Data Display/Save}, and then press the
[YES] key.
5) On the «Data Display Menu» display screen, select the {Data Display} and press the [YES] key.
6) Using the scroll key, scroll the display screen up or down until the desired data is shown.
 A list of the support data is shown in the following table.
Description Display Unit of measure
Battery voltage Battery Voltage V
Vehicle speed signal Meter vehicle speed km/h or MPH
Engine speed signal Engine speed rpm
Engine coolant temperature signal Engine coolant temperature°C or (°F)
Ignition timing signal Ignition timing deg
Throttle position signal Amount of intake air %
Throttle position signal Throttle Sensor Voltage V
Injection pulse width Fuel injection pulse width ms
Idle air control signal ISC Steps STEP
Engine load data Engine load %
Front oxygen (A/F) sensor resistance A/F sensor resistance value 1 ohm
Front oxygen (A/F) sensor output signal A/F sensor current value 1 —
Rear oxygen sensor output signalRear oxygen sensor voltage
valueV
Short term fuel trim A/F Compensation 1 %
Knock sensor signal Knock Correction deg
Atmospheric absolute pressure signal Atmospheric pressure mmHg, kPa, inHg or psi
Intake manifold relative pressure signal Mani. Relative Pressure mmHg, kPa, inHg or psi
Intake manifold absolute pressure signalIntake manifold absolute pres-
suremmHg, kPa, inHg or psi
A/F correction (short term fuel trim) by rear oxygen sensor A/F Compensation 3 %
Long term whole fuel trim A/F learning 1 %
Front oxygen (A/F) sensor heater current Front O2 heater current value A
Rear oxygen sensor heater current Rear O2 heater current value A
Canister purge control solenoid valve duty ratio CPC Valve Duty Ratio %
Fuel level signal Fuel level voltage V
Intake air temperature signal Intake air temperature°C or (°F)
Learned ignition timing Ignition learning value deg
EGR signal EGR Steps STEP
Ignition switch signal Ignition SW ON or OFF
Test mode connector signal Test mode signal ON or OFF
Neutral position switch signal Neutral SW ON or OFF
Air conditioning switch signal A/C SW ON or OFF
Air conditioning compressor signal A/C Compressor Signal ON or OFF
Radiator main fan relay signal Radiator fan relay 1 ON or OFF
Fuel pump relay signal Fuel pump relay ON or OFF
Knocking signal Knock signal ON or OFF
Radiator sub fan relay signal Radiator fan relay 2 ON or OFF
Power steering switch signal Power steering SW input signal ON or OFF
Engine torque control signal #1 AT coordinate request signal 1 ON or OFF
Engine torque control signal #2 AT coordinate request signal 2 ON or OFF

EN(H4SO)-31
ENGINE (DIAGNOSTIC)
Subaru Select Monitor
NOTE:
For detailed operation procedure, refer to the “SUBARU SELECT MONITOR OPERATION MANUAL”.
Engine torque control permission signalAT coordinate permission sig-
nalON or OFF
Rear oxygen sensor rich signal Rear O2 monitor ON or OFF
Starter switch signal Starter SW ON or OFF
Idle switch signal Soft idle SW ON or OFF
Crankshaft position sensor signal Crankshaft position signal ON or OFF
Camshaft position sensor signal Camshaft position signal ON or OFF
Rear defogger switch signal Rear defogger SW ON or OFF
Blower fan switch signal Blower fan SW ON or OFF
Small light switch signal Light SW ON or OFF
AT vehicle ID signal AT/MT identification terminal AT or MT
A/C middle pressure switch signal A/C middle pressure SW ON or OFFDescription Display Unit of measure