I'm not sure if you've done this, but the AFC must be tunned AFTER the bigger injectors are installed.

I don't know your experience or how you tunned this unit, but this unit MUST be tunned using a dyno and a wide band meter. This will ensure you don't lean your engine out to the point of destruction and recieve the maximum performance from the unit. Ultimately, you will get your moneys worth spending a couple hundred bucks to utilize the proper tunning equipment. These units should NOT be tunned using guess work. It's WAY too risky and you are not going to take advantage of the unit to one tenth of it's potential. (Just a friendly reminder to anyone wishing to purchase one of these units).