DTC    P0420    Catalyst System Efficiency Below Threshold (Bank 1)

DESCRIPTION

CONFIRMATION DRIVING PATTERN

INSPECTION PROCEDURE

CHECK OTHER DTC OUTPUT (BESIDES DTC P0420 AND/OR P0430)

CHECK FOR EXHAUST GAS LEAKAGE

INSPECT AIR FUEL RATIO SENSOR (BANK 1, 2 SENSOR 1)

INSPECT HEATED OXYGEN SENSOR (BANK 1, 2 SENSOR 2)