It keeps popping up the P0174 code and I keep smelling gas and rotten eggs . It is back firing and bucking like it’s running out of gas. I have replaced the entire entire exhaust system, fuel system minus the canister, fuel injectors, spark plugs, ignition coil, Throttle body sensor , cam shaft sensor, crank shaft sensor MAP sensor . It does really bad if I get on the highway but I can manage to get around town sort of . Can anybody help ? If it’s the PCM does anybody know a good place to get one.