My sonic will not start it’s throwing a P.O. 420 code and I’ve fixed the sensor smog senor I’ve tried everything and I still can’t get it to start it will turn but not start?,??? I don’t know but I’ve came to my end far as my knowledge of is ending can u help me out so my problem is no start it turns over but will not start do think it could be my starter or could it be my fuel filter or pump.