Subaru Legacy 2002 Service Manual page 1433

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (DIAGNOSTICS)
No.
1 CHECK ANY OTHER DTC ON DISPLAY.
2 CHECK EXHAUST SYSTEM.
Check for gas leaks or air suction caused by
loose or dislocated nuts and bolts, and open
hole at exhaust pipes.
NOTE:
Check the following positions.
¼ Between cylinder head and front exhaust
pipe
¼ Between front exhaust pipe and front cata-
lytic converter
¼ Between front catalytic converter and rear
catalytic converter
3 CHECK REAR CATALYTIC CONVERTER.
Separate rear catalytic converter from rear
exhaust pipe.
4 CHECK FRONT CATALYTIC CONVERTER.
Remove front catalytic converter.
Step
Is there any other DTC on
display?
Is there a fault in exhaust
system?
Is there damage at rear
face of rear catalyst?
Is there damage at rear
face or front face of front
catalyst?
EN(H6)-226
Check Yes
Inspect the rel-
evant DTC using
"17. List of Diag-
nostic Trouble
Code (DTC)".
<Ref. to EN(H6)-
87, List of Diag-
nostic Trouble
Code (DTC).>
NOTE:
In this case, it is
not necessary to
inspect DTC
P0420.
Repair or replace
exhaust system.
Replace front
catalytic converter
<Ref. to
EC(H6)-3, Front
Catalytic Con-
verter.> and rear
catalytic converter
<Ref. to
EC(H6)-6, Rear
Catalytic Con-
verter.>.
Replace front
catalytic con-
verter. <Ref. to
EC(H6)-3, Front
Catalytic Con-
verter.>
No
Go to step 2.
Go to step 3.
Go to step 4.
Contact with your
Subaru distributor
service.
NOTE:
Inspection by
DTM is required,
because probable
cause is deterio-
ration of multiple
parts.