If your loosing coolant from your jug with missfires,it's your intercooler dripping and sucking coolant into your combustion chamber. If your not loosing coolant and the engine missfires while occasionally cutting off,it's your CPS. If you've install a 185 crank pulley and engine missfires or briefly quits running at top end,you need a fuel system upgrade and wideband. That's been my experience anyway. Squirrel Crusher