Subaru IMPREZA 2002 Service Manual page 474

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
ENGINE (DIAGNOSTICS)
Yes
Repair or replace
faulty parts.
Step
7 CHECK EXHAUST SYSTEM.
Check exhaust system parts.
NOTE:
Check the following items.
*Loose installation of portions
*Damage (crack, hole etc.) of parts
*Looseness and ill fitting of parts between front
oxygen (NF) sensor and rear oxygen sensor
No
Replace the rear
oxygen sensor.
<Ref. to
Front Oxygen
(A/
F) Sensor.>
FU( S0HC)-43,
Check
Is there a fault in exhaust sys-
tem?
EN(SOHC)-150