Honda Civic 1998 Service Manual page 294

Misfire Detected in One Cylinder
I P0301 The scan tool indicates Diagnostic Trouble Code (DTC) P030'1: Cylinder 1 misfire detected.
I P0302 ths s636 tool indicates Diagnostic Trouble Code (DTC) P0302: cylinder 2 mistire detected.
119393-.1 Th"""untool indicates Diagnostic Trouble Code {DTC) P03O3r Cylinder3 misfire detected.
P0304 i ths 56sn tool indicates Diagnostic Trouble Code {DTC) P0304: Cylinder 4 misfire detected
Description
Mistire detection is accomplished by monitoring the crankshaft speed with the crankshaft speed fluctuation (CKF) sensor
which is attached to the crankshaft.
lf misfiring strong enough to damage the catalyst is detected,lhe MIL will blink during the time ot its occurrence, and DTC
P0301, P0302, P0303 or P0304 will be stored. Then, after the misfire has ceased, the MIL will come on.
lf misfiring that increases emissions is detected during two consecutive driving cycles, the MIL will come on, and DTC
P0301. P0302. P0303 or P0304 will be stored,
NOTE: lf some of the DTCS listed below are stored at the same time as a mislire DTC, troubleshoot those DTCS first, then
troubleshoot the misfire DTC.
P0106r MAP sensor
P0131, P0132: HO2S
P017'1, P0172t Fuel supply system
P0335, P0336: CKF sensor
P0401, P1491, Pl498: EGR system
P044'l: EVAP system Insufficient purge flow*6
P 1 3 5 9 , P 1 3 6 1 , P 1 3 6 2 : T D C s e n s o r
P l 3 8 1 , P l 3 8 2 : C Y P s e n s o r
* 6 : ' 9 6 D ' 1 6 Y 5 e n g i n e , ' 9 6 D 1 6 Y 7 e n g i n e , ' 9 6 D 1 6 Y B e n g i n e ( s e d a n ) , ' 9 7 D 1 6 Y 5 e n g i n e , ' 9 7 D 1 6 Y 7 e n g i n e ( c o u p e : K A ,
KC models, sedan KA, KC, KL (DX) models, hatchback: all models),'97 D16Y8 engine (sedan: KA, KC models)
Possible Cause
. Fuel injector clogging, fuel leakage, air leakage
. Fuel injector circuit open or shorted
. Spark plug carbon deposits, fouling, malfunction
. lgnition wires open. leaking
. Distributor malfunction
a Compression low
. Valve clearance out of spec
. VTEC system malfunction {D16Y5, D16Y8 engine)
. HO2S
. HO2S circuit
)/
(cont'd)
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