A tune, and a chip are two different things. JET makes that chip I was referring to..plugs into ECU if I'm not mistaken. Trifecta makes a tune specifically for, at least the 2009 model aveo. There are other threads where you'll be able to find more information...just seaarch for trifecta. I am unfamiliar with the maf thing you're talking about, but it isn't what I'm referring to in either case. As far as I know...the only legit tune is through trifecta. Pooh man, I believe got it..I don't recall