Subaru FORESTER 2001 Service Manual page 157

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Engine (Diagnostics)
No.
7 CHECK EXHAUST SYSTEM.
Check exhaust system parts.
NOTE:
Check the following items.
¼ Loose installation of portions
¼ Damage (crack, hole etc.) of parts
¼ Looseness and ill fitting of parts between
front oxygen (A/F) sensor and rear oxygen
sensor
Step
Is there a fault in exhaust
system?
EN(DOHC TURBO)-156
Check Yes
Repair or replace
faulty parts.
No
Replace rear oxy-
gen sensor. <Ref.
to FU(DOHC
TURBO)-44, Rear
Oxygen Sensor.>