Ok, I just changed my LIM gasket, new Plenum, flushed and changed the anitfreeze and switched to the green stuff, and while doing so I changed my spark plugs and wires. Its all put back together and it started up perfectly and then i let it run and was reving it up, then my Service Engine Soon light was flashing. and in the book that says it is misfireing. . . What do i do???