Need suggestions about finding problem with fuel/air mix. Where do I begin? Manuel sucks, shop to much money, I can do this! 1. smog fail,to much fuel in exhaust,misfiring, HC and CO way over. 2. did tune up,yes me, didnt make much difference in recheck. Fuel injection He says! Is it too much fuel or not enough air? There is a difference right? What is the diagnosis process at home mind you. HELP!