DTC    P0420    Catalyst System Efficiency Below Threshold (Bank 1)

MONITOR DESCRIPTION

CONFIRMATION DRIVING PATTERN

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0420, P0430)

PERFORM ACTIVE TEST BY INTELLIGENT TESTER (CONTROL THE INJECTION VOLUME FOR A/F SENSOR)

CHECK FOR EXHAUST GAS LEAKAGE

REPLACE THREE-WAY CATALYTIC CONVERTER (EXHAUST MANIFOLD)