Be wary...among other things, some aftermarket chips simply re-configure the throttle position--for example, when you push down halfway on the gas pedal, it'll tell the engine that you're pushing it all the way to the floor. The rsult is that at first you feel like you're flying, but there's little to no performance after this "100% throttle" position has been hit. It also is a great way to waste fuel.
But hey, that's only my personal experience.