1.9 ltr DOHC engine. Recently replaced PMC when Service Engine, Battery symbol, Service lights started popping on and off while tach dropped to zero while running and misfiring. Also replaced alternator. Nobody can give me the cause. Dealership shows no codes but car runs great for a few minutes then dash lights go berzerk and it starts misfiring. All grounds have been checked and cleaned. Please help me I don't have a clue what to do to fix the problem(s) ?