Subaru IMPREZA 2002 Service Manual page 471

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
ENGINE (DIAGNOSTICS)
Step
CHECK ANY OTHER DTC ON DISPLAY.
CHECK EXHAUST SYSTEM.
NOTE:
Check the following items.
*Loose installation of front portion of exhaust
pipe onto cylinder heads
$Loose connection between front exhaust pipe
and front catalytic converter
*Damage of exhaust pipe resulting in a hole
Check
)oes the Subaru Select Moni-
or or OBD-ll general scan tool
ndicate DTC PO1 31, PO1 32,
'0031 or P0032?
s
there a fault in exhaust sys-
em?
Yes
Inspect DTC
PO1 31, P0132,
PO031
or
PO032
using "List of Diag.
nostic Trouble
Code (DTC)".
<Ref. to
List of Diagnostic
Trouble Code
(DTC).>
NOTE:
In this case, it i :
not necessary tc
inspect DTC
PO1 33.
Repair exhaust
system.
EN(S0HC)-77,
No
20 to step 2.
3eplace the front
)xygen
(NF)
sen-
;or. <Ref. to
'ront Oxygen
(A/
7
Sensor.>
'U(SOHC)-43,
EN(S0HC)-147