Subaru Legacy 2002 Service Manual page 1184

6) Remove spark plug with the spark plugs socket.
B: INSTALLATION
1. RH SIDE
S101003A1105
Install in the reverse order of removal.
Tightening torque (Spark plug):
21 N·m (2.1 kgf-m, 15 ft-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.
Tightening torque (Ignition coil):
16 N·m (1.6 kgf-m, 12 ft-lb)
2. LH SIDE
S141003A1106
Install in the reverse order of removal.
Tightening torque (Spark plug):
21 N·m (2.1 kgf-m, 15 ft-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.
Tightening torque (Ignition coil):
16 N·m (1.6 kgf-m, 12 ft-lb)
C: INSPECTION
Check electrodes and inner and outer porcelain of
plugs, noting the type of deposits and the degree
of electrode erosion.
SPARK PLUG
B2M4333
S141003A11
S141003A10
(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.
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.
IG(H6)-5
Ignition
B2M4334B
G6M0087
G6M0088