2003 HONDA CIVIC Pipe

lntake Manifold and Exhaust System
Exhaust Pipe and Muffler Replacement
SELF-LOCKING NUT10 x 1.25 mm33 N.m {3.4 kgf.m,25 rbf.ft)Beplace.
8 x 1.25 mm22 N.m {2.2 kgf m, 16lbf.ft)Replace.Tighten the bolts in steps,alternating side to-side.
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NOTE: Use new gaskets and self-locking nuts when reassembling.
8 x 1.25 mm22 N.m (2.2 kst.m. 16lbf.ftlReplace.Tighten the bolts in steps,alternating side'to side.
EXHAUST PIPE B
HEAT SHIELD\,
6x1.0mm9.8 N.m{1.0 kgt.m, 7.2 lbf ft}
GASKETReplace.
SECONDARY HEATEDOXYGEN SENSOR{SECONDARY HO2SIil4Nm(4.5 ksf.m,33 lbf.ftl
AIR FUEL RATIO {A/F)SENSOR44 N.m (it.s kgf.m, 33 lbf ftl
9-8
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Cooling System
Component Location Index
WATER PUMPInspection, page 10-5Replacement. page 10-5
RESERVETANK
RADIATORCAP
RAOIATOR FAN SWITCHTest, page 10-17Replacement, page 10'17
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WATER OUTLET,Installation, page'10-g
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CONNECTING PIPE
WATER PASSAGEInstallation, page 10-9
THERMOSTATTest, page 10 4Replacement, page 10 8
RADIATORReplacement, page 10-'l0
RADIATOR FANASSEMgLYReplacement, page 10-10Fan MotorTest, page 10 4A/C CONDENSERFAN ASSEMBLYReplacement, page 10 10Fan Motor Test, page '10-4
10-2
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SymptomDiagnostic procedureAlso check torDifficult to refuel(MlL works OK. no DTCS set)
1. Testthefuel tank vapor control valve{seepage 1'l-
2. 1471.
Inspect the fuel tank vapor control signal tube
3. between the fuel pipe and the fuel tank vapor
control valve.
4. Inspect the fuel tank vapor vent tube between the
EVAP canister and the fuel tank vapor control valve.
Check the EVAP canister.
Malfunctioning gas
station filling nozzle.
Fuel overflows during
refueling(No DTCS set)
Replace the fuel tank vapor control valve (see page '1 1
189).
Malfunctioning gas
station filling nozzle.
11-11

Fuel and Emissions Systems
System Descriptions (cont'dl
Gatalytic Converter System
Three Way Catalytic Converter (TWC)
The TWC converts hydrocarbons (HC), carbon
monoxide {CO), and oxides of nitrogen (NOx) in the
exhaust gas to carbon dioxide (C02), dinitrogen (N2),
and water vaDor.
THREE WAYCATALYST
FRONT OFVEHICLE
11-34
Positive Crankcase Ventilation (PCVI System
The PCV valve prevents blow-by gasses from escaping
into the atmosphere by venting them into the intake
manifo ld.
:: BLOW-BY VAPOR€: FRESH AIR
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BREATHER PIPE
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Fuel and Emissions Systems
System Descriptions (cont'dl
ldle Control System Diagram
The idle speed of the engine is controlled by the ldle Air Control (lAC) varve:
'Aftertheenginestarts,theIACvalveopensforacertainamountoftime.Theamountofairisincreasedtoraisethe
idle sDeed.. When the engine coolant temperature is low, the IAC valve is opened to obtain the proper fast idle speed. Theamount of bypassed air is controlled in relation to engine coolant temperature.
INTAKE MANIFOLDIAC VALVEAKE AIR DUCT
CLEANER
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BLK/REO
YEL/BLK ---< FromPGM.FIMAINRELAY
THROTTLE AODY
Intake Air System Diagram
This system supplies air for engine needs. A resonator in the intake air
drawn into the svstem.
VARIOUSSENSOnS
pipe provides additional silencing as air is
THROTTLE AODYVARIOUSSENSORS
BLK
BLK
I
11-36
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DTC P0134: Ay'F Sensor (Sensor 1) No Activity
Detected
1. Check the attachment state of the A,/F sensor(Sensor 1).
ls it slacked f rom the exhaust pipe?
YES- Reinstall the Ay'F sensor (Seneor 1) (see page
11-113).t
NO-Go to step 2.
2. Reset the ECM (see page 1 1-4).
3. Stan the engine. Hold the engine speed at
3,000rpm with no load (in neutral) until the radiator
fan comes on, then let it idle for 2 minute.
ls DTC PO134 indicated?
YES-Replace the Ay'F sensor {Seneor 1) (see page
11-113).t
NO - Intermittent failu re, sistem is OK at this time.
Check for poor connections or loose terminals at
the Ay'F sensor (Seneor 1 ) and the ECM.I
DTC P0137: Secondary HO2S (Sensor 2)
Circuit Low Voltage
1. Reset the ECM (see page I1-4)
2. Start the engine. Hold the engine at 3,000 rpm wilh
no load (in neutral) until the radiator fan comes on.
3. Check the secondary HO2S (Sensor 2) output
voltage at 3,000 rpm with the scan tool.
ls there 0.3 V or less?
YES Go to step 4.
NO-lntermittent failure, system is OK at this time.
Check for poor connections or loose terminals at
the secondary HO2S (Sensor 2) and at the ECM.I
Turn the ignition switch OFF.
Disconnect the secondary HO2S (Sensor 2) 4P
connector.
Turn the ignition switch ON (ll).
Check the secondary HO2S (Sensor 2) output
voltage with the scan tool.
ls there 0.3 V or less?
YES Go to step 8.
NO Replace the secondary HO2S (Sensor 2).1
Turn the ignition switch OFF.
Disconnect ECM connector E (31P).
icont'd)
4.
5.
6.
7.
8.
9.
11-65

PGM-FI System
DTC Troubleshooting (cont'dl
DTC P0171: Fuel System Too Lean
DTC P0172: Fuel System Too Rich
NOTE: lf some of the DTCS listed below are stored at
the same time as DfC PO17'l and/ot PO172,
troubleshoot those DTCS first, then recheck for P0171
andlot P0112.
P0107, P0108. P1 128. P1 129: Manifold absolute
pressure (MAP) sensor
P1 162. P1 166, P 1 167: 4,,/F sensor (Sensor 1 ) heater
P0137, P0138: Secondary HO2S (Sensor 2)
P014'l: Secondary HO2S (Sensor 2) heater
P1259: VTEC system
1. Check the fuel pressure (see page 11-'145).
ls luel pressure OK?
YES Go to step 2.
NO Check these items:
. lf the pressure is too high, replace the fuel
pressure regulator (see page 11-152).1. lf the pressure istoo low.checkthefuel pump,
the fuel feed pipe, the fuel filter, and replace the
fuel pressure regulator (see page 11-152).I
2. Start the engine. Hold the engine at 3,000 rpm with
no load (in neutral) until the radiator fan comes on.
11-70
3. Turn the ignition switch OFF.
4. With a vacuum pump, apply vacuum to the
evaporative emission (EVAP) canister purge valve
(A) from the evaporative emission (EVAP) canister
side.
' A973AX-041-XXXXX
Does it hold vacuum?
YES-Check the engine valve clearances and adjust
if necessary, lf the valve clearances are OK, replace
the injectors (see page 1 1-1 1 1).1
NO-Replace the EVAP canister purge valve.l

Fuel Tank Replacement
Relievethefuel pressure (see page 11-144).
Drain the fuel tank: Remove the fuel pump (see page 1 1-153). Using a hand pump, hose, and container suitable for
gasoline. draw the fuel from the fuel tank.
Jack up the vehicle, and suppon it with safety stands.
Remove the fuel pipe cover (A). Disconnect the fuel vapor hose and quick-connect fittings.
Disconnect the hoses. Slide back the clamps (B), then twist the hoses as you pull to avoid damaging them.
A 38 N.m(3.9 ksf.m,28lbfft)
5. Place a jack or other support under the tank.
6. Removethe strap bolts, and letthestrap (C) hangfree.
7. Remove the fuel tank (D). lf itstickstothe undercoaton its mount, carefully pry itoffthe mount
8. Install the parts in the reverse order of removal.
1.
2.
3.
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11-155