Subaru IMPREZA 2002 Service Manual page 493

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
ENGINE (DIAGNOSTICS)
Yes
Repair or replace
faulty parts.
NOTE:
Check the fol-
Spark plugs
Fuel injectors
Ignition coil
If no abnormal is
discovered, check
for "16. D: IGNI-
TlON CONTROL
SYSTEM" of #3
and #4 cylinders
side. <Ref. to
lowing items.
EN(S0HC)-66,
IGNITION CON-
TROL SYSTEM,
Diagnostics for
Engine Starting
Failure. >
Repair or replace
faulty parts.
Check the follow-
Spark plugs
Fuel injectors
Skipping timing
belt teeth
NOTE:
ing items.
Repair or replace
faulty parts.
Check the follow-
Spark plugs
Fuel injectors
Compression
ratio
Skipping timing
belt teeth
Go to DTC PO1 70.
<Ref. to
EN(S0HC)-154,
DTC PO171
-
FUEL TRIM MAL-
FUNCTION (NF
TOO LEAN)
-,
Diagnostic Proce-
dure with Diagnos-
tic Trouble Code
(DTC).>
NOTE:
ing items.
Step
GROUP OF #3 AND #4 CYLINDERS
! 3
No
Go to DTC PO1 70.
<Ref. to
DTC PO171
-
FUNCTION (NF
TOO LEAN) -,
Diagnostic Proce-
dure with Diagnos.
tic Trouble Code
(DTCI.2
EN(SOHC)-154,
FUEL TRIM MAL-
Go to DTC P0170.
<Ref. to
DTC PO171
-
FUNCTION ( N F
TOO LEAN)
-,
Diagnostic Proce-
dure with Diagnos,
tic Trouble Code
(DTC).>
Go to DTC P0170.
<Ref. to
DTC PO171
-
FUNCTION (NF
TOO LEAN)
-,
Diagnostic Proce-
dure with Diagnos
tic Trouble Code
(DTC).>
Repair or replace
faulty parts.
NOTE:
Check the follow
ing items.
Spark plugs
Fuel injectors
Compression
ratio
EN(SOHC)-l54,
FUEL TRIM MAL-
EN(S0HC)-154,
FUEL TRIM MAL-
!4
GROUP OF #I AND #3 CYLINDERS
2 5
GROUP OF #2 AND #4 CYLINDERS
!6 CYLINDER AT RANDOM
Check
ire there faults in #3 and #4
:ylinders?
Ire there faults in #1 and #3
:yl inde rs?
ire there faults in #2 and #4
:ylinders?
s the engine idle rough?
EN(S0HC)-169