Subaru Impreza 2004 Service Manual page 56

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
Y: DTC P0134 O2 SENSOR CIRCUIT NO ACTIVITY DETECTED (BANK 1 SEN-
SOR 1)
NOTE:
For the diagnostic procedure, refer to DTC P0130. <Ref. to EN(H4DOTC)(diag)-132, DTC P0130 O2 SEN-
SOR CIRCUIT (BANK 1 SENSOR 1), Diagnostic Procedure with Diagnostic Trouble Code (DTC).>
Check
Is any other DTC displayed?
Is there a fault in exhaust sys-
tem?
EN(H4DOTC)(diag)-135
ENGINE (DIAGNOSTICS)
Yes
Inspect the rele- Go to step 2.
vant DTC using
"List of Diagnostic
Trouble Code
(DTC)". <Ref. to
EN(H4DOTC)(dia
g)-74, List of Diag-
nostic Trouble
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(H4DOTC)-44,
Front Oxygen (A/
F) Sensor.>
No