well my car stutters and misfires when I go WOT and it's between 3-4k rpm. After 4k it just boosts fine. So I would get the infamous CEL 43. I would disconnect the battery and reconnect it. Well for first 5-10 minutes black smoke would just come pouring out of the exhaust and the engine would idle very rough. After 10 minutes engine idles fine and runs fine. So my conclusin was, I flooded the engine with too much gas and me running 94 all the time just help with the rich mixture even more. So make sure you guys are running effecient amount of fuel and not more or less.