Subaru Legacy 2004 Service Manual page 547

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step
1 CHECK ANY OTHER DTC ON DISPLAY.
2 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
Is any other DTC displayed?
Is there any fault in exhaust
system?
EN(H4SO 2.0)(diag)-115
ENGINE (DIAGNOSTICS)
Yes
Check DTC using Go to step 2.
"List of Diagnostic
Trouble Code
(DTC)". <Ref. to
EN(H4SO
2.0)(diag)-66, List
of Diagnostic Trou-
ble Code (DTC).>
NOTE:
In this case, it is
not necessary to
inspect DTC
P0133.
Repair the exhaust Replace the front
system. oxygen (A/F) sen-
sor. <Ref. to
FU(H4SO 2.0)-32,
Front Oxygen (A/
F) Sensor.>
No