Subaru Impreza 2003 Service Manual page 1336

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
ENGINE (DIAGNOSTICS)
AM:DTC P0304 — CYLINDER 4 MISFIRE DETECTED —
• DTC DETECTING CONDITION:
• Two consecutive driving cycles with fault
• Immediately at fault recognition (A misfire which could damage catalyst occurs.)
• TROUBLE SYMPTOM:
• Engine stalls.
• Erroneous idling
• Rough driving
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4DOTC)-48, OP-
ERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4DOTC)-40, Inspection Mode.>.
• WIRING DIAGRAM:
EN(H4DOTC)-160