Some vehicles may experience the Check Engine Light ON with DTC P0300:00, P0301:00, P0302:00, P0303:00 and/or P0304:00 stored in memory. P0300:00: Random misfire detected, P0301:00: Cylinder No.1 misfire detected, P0302:00: Cylinder No.2 misfire detected, P0303:00: Cylinder No.3 misfire detected, P0304:00: Cylinder No.4 misfire detected. Carbon may be deposited around the intake valves, resulting in unstable engine combustion and misfiring during the accelerated warm-up system (AWS) operation.