Can anybody recommend from experience a good brand of obdII tuner? I've got a suburban with a 5.3, since I put a CAI on, it has been finicky, pre-ignition, pingy with 87 pump gas. Clears right up when I pop for 93 octane. But that's getting kinda expensive lately. I know I could take it into most tuning shops and get hooked up for around tre-fiddy, but that's about the price of some of the tuners I've seen on fleabay. I won't learn anything by having it done for me, and maybe I can use it for other vehicles. Soooooo, anybody got a suggestion? Colin