Subaru IMPREZA 2002 Service Manual page 299

SPARK PLUG
IGNITION
5) Remove the spark plug cords by pulling boot, not
cord itself.
I
6) Remove the spark plugs with the spark plug
sockets.
I , ,
I
B: INSTALLATION
1. RH SIDE
1) Install in the reverse order of removal.
Tightening torque (Spark plug):
27 Nom (2.7 kgf-m, 75 ff-lb)
CAUTION:
The above torque should be only applied to
new spark plugs without oil on their threads.
In case their threads are lubricated, the torque
should be reduced by approximately 1/3 of the
specified torque in order to avoid over-stress-
ing.
2. LH
SIDE
1) Install in the reverse order of removal.
Tightening torque (Spark plug):
CAUTION:
The above torque should be only applied to
new spark plugs without oil on their threads.
In case their threads are lubricated, the torque
should be reduced by approximately
1/3
of the
specified torque in order to avoid over-stress-
ing.
27 N-m (2.7 kgf-m, 75 ff-lb)
C: INSPECTION
Check the electrodes and inner and outer porcelain
of plugs, noting the type of deposits and the degree
. -
of electrode erosion.
i
S6M0420F
( E )
(A) Electrode gap
(B) Carbon accumulation or wear
(C) Cracks
(D) Damage
(E) Damaged gasket
1) Normal:
Brown to grayish-tan deposits and slight electrode
wear indicate correct spark plug heat range.
G6M008i
2) Carbon fouled:
Dry fluffy carbon deposits on insulator and elec-
trode are mostly caused by slow speed driving in
city, weak ignition, too rich fuel mixture, dirty air
cleaner, etc.
It is advisable to replace with plugs having hotter
heat range.
G6M0088
IG(S0HC)d