Subaru 2004 LEGACY Service Manual page 115

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step
27 GROUP OF #2, #4 AND #6 CYLINDERS.
28 CYLINDER AT RANDOM.
Check
Is there any fault in #2, #4 and
#6 cylinders?
Is the engine idle rough?
EN(H6DO)(diag)-184
Yes
Repair or replace Inspect the DTC
the faulty part. P0171, P0172,
P0174 or P0175
NOTE:
using "List of Diag-
Check the follow-
nostic Trouble
ing items:
Code (DTC)".
• Spark plug
<Ref. to
• Fuel injector
EN(H6DO)(diag)-
• Compression
66, List of Diag-
ratio
nostic Trouble
• Skipping timing
Code (DTC).>
chain teeth
Inspect the DTC Repair or replace
P0171, P0172, the faulty part.
P0174 or P0175
NOTE:
using "List of Diag-
Check the follow-
nostic Trouble
ing items:
Code (DTC)".
• Spark plug
<Ref. to
• Fuel injector
EN(H6DO)(diag)-
• Compression
66, List of Diag-
ratio
nostic Trouble
Code (DTC).>
No