Exhaust System HONDA CIVIC 1998 6.G User Guide

PGM-FI System
Fuel Supply System
D017-il Th""""ntool indicates Diagnostic Troubte Code {DTC) p0171;Thefuet system istoo lean.
1P0172 | fne scan tool indicates Dlagnostic Trouble Code (DTC) P0172:Thefuel system istoo rich.
Description
By monitoring the Long Term Fuel Trim, long term malfunctions in the fuel system will be detected.lf a malfunction has been detected during two consecutive trips, the MIL will come on and DTC P0171 and/or P0172 will bestored.
NOTE: lf some of the DTCS listed below are stored at the same time as DTC P0171 andlot P0172, ltouhleshoot those DTCSfirst. then recheck for DTC P0l7l andlot P0172.
P0106-8, P1128*3. *5, P1129*3 *5 MAP Sensor
P0135; Primary HO2S Heater
P0137. P0138: Secondary HO2S
P0'141: Secondary HO2S Heater
P0401: EGR Flow Insufficient*1
P0441: EVAP System Insufficient Purge Flow*6
P1259: VTEC System*,
P1491:EGR Valve Lift Insufficient*r
P1498: EGR Valve Lift Sensor Hjgh Voltage*r
*r: D16Y5 engines*': Dl6Y5, D16Y8, 81642 engine*3: '97 models*a:'96 modelsf 5: '98 - 00 models*6: '96 D16Y5 engine,'96 D16Y7 engine,'96 D16Y8 engine (sedan),'97 D16y5 engine,,97 D16y7 engine (coupe: KA, KC mo+els, sedan KA. KC, KL (DX) models. hatchback; all models),'97 D16Y8 engine (sedan: KA, KC models)
Possible Cause
DTC P0'171
loo lean
DTC P0172
too rach
Fuel Pump insuff icient f lovpressure
Fuel Feed Line clogged, leaking
Fuel Pressure Regulator stuck open
Fuel Filter clogged
Fuel Injector clogged, air inclusion
Gasoline doesn't meet Owner's Manual spec.
Primary HO2S (Sensor 1) deteriorated
MAP Sensor range/performance*.
EGR System malfunction (too much flow)*1
Valve Clearance
Exhaust leak
Fuel Pressure Regulator clogged, stuck closed
Fuel Return Pipe clogged
Fuel Injector leaking
Gasoline doesn't meet Owner's Manual spec.Primary HO2S (Sensor 1) deteriorated
MAP Sensor range/performance*a
EGR System insufficient flow*1
EVAP Purge Control Solenoid Valve leaking, stuck opened
Valve Clearance
11-164

Emission Gontrol System
System Description
The emission control system includes a Three Way Cata-lytic Convener (TWC), Exhaust Gas Recirculation (EGR)
system,. Positive Crankcase Ventilation (pCV) system andEvaporative Emission (EVAP) Control system. The emis-sion control system is designed to meet federal and stateemission standards.*: D16Y5 engine
Tailpipe Emission
Inspestion
@@ Do not smoke during ihis procedure. Keepany open flame away from your work area.
1. Start the engine. Hold the engine at 3,000 rpm withno load (in Park or neutral) until the radiator fancomes on. then let it idle.
2. Connect a tachometer.
Check and, if necessary, adjust the idle speed (see
page 11-220 - 223).
Warm up and calibrate the CO meter according to themeter manufacturer's instructions.
Check idle CO with the headlights, heater blower,rear window defogger, cooling fan, and air condition-er off.
NOTE: (Canada) Pull the parking brake lever up.Start the engine, then check that the headlights areoff.
CO mete. should indicate 0.1% maximum.
NOTE: '98 Dl6Y5 engine - lf the idle speed incress-es to 8101 50 rpm, this means the EVAp system ispurging the canister. To stop the purging temporari-ly. raise the engine speed above 1,000 rpm with theaccelerator pedal, then slowly release the pedal.
11-252
eFORWARD -
Three Way Catalytic Converter
(TWCI
Doscription
The Three Way Catalytic Converter (TWC) is used toconven hydrocarbons (HC), carbon monoxide (CO), andoxides of nitrogen (NOx) in the exhaust gas to carbondioxide (COr), dinitrogen (N,) and water vapor.
D15Y5, D16
, engine:
'99 - 00 D16Y8, 81642 engine:
ENGINE SIDE
t

\
lTo420l Th" """n toot indicates Diagnostic Troubte code (DTc) p0420: catatyst sysrem efficiency below threshold.
Description
This system evaluates the catalyst's capacity by means of the Ho2s {Primary and secondary) output during stable driving
conditions. ll deterioration has been detected during two consecutive driving cycles. the MIL comes on and DTC P0420 will
be stored.
NOTE: lf some of the DTCS tisted below are stored at the same time as DTC P0420, troubleshoot those DTCS first. then
recheck for DTC P0420
P0137, P0138: Secondary HO2S (Sensor 2)
Po14'1:Secondary H02S {Sensor 2) Heater
Possibl€ Cause
. TWC Deterioration
. Exhaust system leakage
Troubleshooting Flowchart
I
The MIL has been reported on.
DTC P0420 is stored
Problem verilication:1. Do the ECM/PCM Reset Proce
dure.2. Start the engine Hold the
engine at 3,000 rpm wath no
load {in Park or neutral) until
the radiator fan comes on.
3. Connect the SCS service con
4. Test drive 40 - 55 mph for
approx, two minutes Then
decelerate for at least 3 sec_
onds with the throttle com'pletely closed- Then reduce
the vehicle speed to 35 mph,
and try to hold it until the
readiness code comes on
Intermittent Iailure, system is OK
at this time.ls DTC P0420 indicated?
Check the TWC {see section 9l
lf necessary, replace the TwC

Emission Control System
Exhaust Gas Recirculation (EGR) System (D16yS engine)
Doscription
The EGR system is designed to reduce oxides of nitrogen emissions (NOx) by recirculating exhaust gas through the EGRvalve and the intake manifold into the combustion chambers. lt is composed of the EGR valve. EGR vacuum conrrot vatve.EGR control solenoid valve. ECM and various sensors.The EcM contains memories for ideal EGR valve lifts for varying operating conditions, The EGR valve lift sensor detectsthe amount of EGR valve lift and sends the information to the ECM. The ECM then compares it with the ideat EGR valve liftwhich is determined by signals sent from the other sensors. lf there is any difference between the two. the EcM cuts cur-rent to the EGR control solenoid valve to reduce vacuum applied to the EGR valve.
EGR CONTROLCVT: SOLENoID vALvE
EGN VALVE LIFT SENSOR
BLK
I
I
11-254

Emission Control System
Exhaust Gas Recirculation (EGR) System (D16Y5 engine with GWI (cont'dl
lTl49il T_he scan tool indicates Diagnostic Trouble Code (OTC) P1491: A malfunction in the Exhaust Gas Recirculation- lEgh) svstem.
CvT lM/T see page 1l-2611:
J
EGR VALVELIFT SENSOR#16 HOSE
PUMP/GAUGE,0- 30 in.HsA973X-041-XXXXX
EGRVALVE
The MIL has been reoorted on.DTC P1491 is stoled.
Problem verification:1. Do the ECM/PCM Reset Proce-du re.2. Connect the SCS service con'
3. Start the engine. Hold theengine at 3,000 rpm with noload {in Park or neutral) untilthe radiator fan comes on,4. Drive the vehicle on the roadfor approx. 10 minutes. Try tokeep the engine speed in the1,700 - 2,500 rpm range.
Intermittonl failure, system is OKat this time. Check for Door con-nections or loose wires at, C144{EGR velve} and ECM/PCM.
ls DTC P l49l indicated?
Check fo. vacuum to ihe EGR
1. Disconnect the No. 16 hose fromthe EGR valve.2. Connect a vacuum pump/gauge to the hose.3. Start the engine and let it idle.
ls there any vacuum?
Check tor a malfunction in theEGR control solenoid valve:'1. Disconnect the EGR controlsolenoid valve 2P connector,2. Becheck the No. 16 hose for
Check vacuum hose routing o,the entire EGR svstem. lf hoserouting is OK, replac€ the EGRcontrol solenoidvalv6.
ls there any vacuum?
Substitute a known-good ECM/PCM and recheck. It symptom/indicalion goes away, replacethe original ECM/PCM.
(To page 11 257)
11-256

Emission Gontrol System
Exhaust Gas Recirculation (EGRI System (Dl6Y5 engine with CW) (cont'dl
EGR VALVE LIFT SENSOR3P CONNECTOR {Cl251
./
EGR L(WHT/BLKI
EGR LIWHT/BLKI
EGR L{WHT/BLKI
sG2
{GRN/BLK}
sG2{GRN/BLK}
Terminal side ol male terminal
ECIT'I CONNECTOR D II6PI
Wir€ side of f€male terminals
PCM CONNECTORS C (31PI*
{To page 11-259)
11-258
{From page 11-257}
Chock lor an opcn or short in th.EGR v.lve lift .€nsor'1. Turn the ignition switch OFF.2. At the sensor sid€, measur€resistance between the EGRvalve lift sensor 3P connectorterminals No. 1 and No.2.
ls there continuity or resis'tance ot 100 k0 or higher?
Chock tor sn op€n or lhort in theEGR valve lift lonror:Measure resistancg between theEGR valve lift s€nsor 3P connec-tor terminals No. 1 and No. 3.
ls there 100 k0 or higher?
Ch.ck tor an ooon or rhon in thcwiro IEGRL linc):1. Beconnect tho EGR v6lve liftsensor 3P connector.2. Turn tho ignition switch ON (ll).
3. Measure voltage between theECM/PCM connector terminalsD9 and Dl1 (C6 and C18l*.
ls there approx. 1.2 V?
(To page 11-259)
Wire side of female terminals

Emission Control System
Exhaust Gas Recirculation (EGR) System (Dl6Y5 engine with CW) (cont'dl
tJ
(From page 11-259)EGR CONTROL SOLENOIDVALVE 2P CONNECTOR {C142}
Wire sideof lemaleterminals
ECMCONNECTORa t32Pl
Chock lor an open in the wire (E
SOL linsl:1. Turn the ignition switch OFF.2. Disconnect the 2P connectorIrom the EGR control solenoid
3. Disconnect the ECN4/PCM con-nector A (32P) (B (25P))* fromthe EcM/PCM.4. Check tor continuity betweenECM/PCl, connector terminal47 (86)* and the EGR controlsolenoid valve 2P connectorterminal No.2.
Repair opon in th. wir. bstwocntha EGR control 3ol€noid valvoand tho ECM/PCM (A7 186l'1.
ls there continuity?
Check for . rhort in the wire(ESOL linel:Check for continuity between theEGR controlsolenoid valve 2P con-nector terminal No. 2 and bodyground,
R.p.ir ahort in tha wi.c b.twecnthe EGR control iolonoid vllyeand th. ECM/FCM {A7 (46}rl.
Check for an opon in the wiroIGND linel:Check for continuity between theEGR controlsolenoid vaive 2P con-nector terminal No. I and bodyground,
Rcpai. op€n in the wir6 b6'twoenthe EGR control rol.noid valveand G101.
Sub3titule a known-good ECM/PCM and rechock. lf symptom/indication goes away, replac€the original ECM/PCM.
ESOL
IRED)
ESOLIRED)
Wire sideof femaleterminals--_-]
I
EGR CONTROL SOLENOIDVALVE 2P CONNECTOR ICl'2}
Wire sideof femaleilterminals
ECMCONNECTORB l25P)ESOL(REDI
Wire sideof femalerermtnats
*: '99 - 00 models
11-260

\JExhaust Gas Recirculation System (D16Y5 engine with M/T)
M/T:
EGR VALVE 6P CONNECTOB (C14'rl
G10lIBLK}
1
a
PNK
IE.EGRI
Wi16 side of male terminals
I
sG2{GRN/BLK}
vcc2{YEL/BLU)
- Th6 MIL ha3 b€on reponed on.- DTC Pl,{tl is 3tored.
Prcblem verification:1. Do the ECM Reset Procedure.
2. Connect the SCS service con_nector.3. Start the engine. Hold the
engine at 3,000 rpm with no
load (transmission in neutral)
untilthe radiator fan comes on.
4. Drive the vehicle on the road
for approx. 10 minutes. Try to
keep the engine speed in the
1,700 - 2,500 rpm range.
lnlermittont tailure, svalem is OK
at thi3 tim6. Check foi Poor con'
nections or looso wiro3 at Cl/K
IEGR valvsl and ECM.
ls DTC P1491 indicated?
Check tor a malfunction in the
EGR valv6:1. Turn the ignition switch OFF.
2. Disconnect the EGR valve 6P
connector.3. Stanthe engine and let it idle
4. Measure voltage between the
EGR valve 6P connector termi'
nals No.4and No.6.
Check the EGR valve:1. Turn the ignition switch OFF2. Turn the ignition switch ON lll).3. Measure voltage between theEGR valve 6P connector termi
nals No.2 and No.3.
ls there battery voltage?
Substitute a known-good ECM
and recheck. It symptom/indica_tion goes away, replace th€ origi-
nal ECM.
ls there approx.5V?
(To page 11-262)

Emission Control System
(From page 11-261)
Check tor open in the wire (SG2
linel:Measure voltage between theECM connector terminals D10and D11.
Repsir open in lhe wire beiweenECM lOllland EGR valve.ls there approx. 5 V?
Check the EGR valve:1. Turn the ignition switch OFF.2, At the sensor side, measureresistance between the EGRvalve 6P connector terminalsNo. 1 and No. 2.
ls there continuity or resis-tance of 100 k0 or higher?
Check the EGR valve:Measure resistance between theEGR valve 6P connector terminals No. 1 and No.3.
ls there 100 k0 or higher?
Exhaust Gas Recirculation System (D16Y5 engine with M/T) (cont'dl
ECM CONNECTOR D {16P)
vcc2(YEL/BLU)
\v
sG2IGRN/BLK)
Wire side of female term;nals
EGR VALVE 6P CONNECTOR
EGR L(WHT/
BLK}
SG2 (GRN/BLK)
Termanal side of male terminals'l'
EGR L{WHT/BLK}
vcc2
{YEL/BLU}
(To pase 11 263)
1-262

Emission Gontrol System
Exhaust Gas Recirculation System (Dl6Y5 engine with M/Tl (cont'dl
lFrom page 11 263)EGR VALVE6P CONNECTOR {C144}
J
Wire sideof femaletermtnals
J
Check lor an op€n in the wire (E-
EGR line):1. Turn the ignition switch OFF.2. Disconnect the ECM connector,A (32P)trom the ECM.3. Check lor continuity betweenECM connector terminal A7and the EGR valve 6P connec-torterminal No. 6.
Repair open in the wiro botweenthe EGR valv6.nd th€ ECM {A71.
Check tor a short in the wire {E-EGR lin6l:Check for continuity betweenECM connector terminal A7 andbody ground.
Reoair shorl in tho wiro belwe€nthe EGn vake rnd the ECM lA7l.ls there continuity?
Check fo. an open in tho wiro
IGND line):Check for continuity between theEGR valve 6P connector terminalNo.4 and body ground.
R6pai. open in th€ wir. betweenth6 EGF control solenoid v6lveand G101.
Substitute 8 known-good ECMand recheck. It symptom/indica-tion goes away, roplace the origi-nalECM.
CONNECTORA l32P)
2
a
I G101
Q) raur
-264