P0420

DTC P0420 - CATALYST SYSTEM EFFICIENCY BELOW THRESHOLD (CAT)





SUBARU SELECT MONITOR DISPLAY





FLOW CHART

DTC DETECTING CONDITION:
- Immediately at fault recognition (2200 cc all states except California model only)
- Two consecutive trips with fault

TROUBLE SYMPTOM:
- Engine stalls.
- Idle mixture is out of specifications.

CAUTION: After repair or replacement of faulty parts, conduct CLEAR MEMORY and INSPECTION MODES.





WIRING DIAGRAM











PROCEDURES