LOL without putting a co meter upthe cars exhaust you aint gonna have a clue wther its overfueling or not TBH, just take it to a tuner or even a garage that does emissions testing.. if the co is stupidly high then its going to be overfueling.. it set it correctly however takes a bit more than just a fiddle.. as the fueling need to be right on pull throttle/boost as well as idle.. so you will have to drive down the road with a co meter in the exhaust