People have been making these for, and using them on, fuel injected cars since Air temp sensors and O2 sensors have been in use. What it does is trick the ECU into believing that the air coming into the ATS is cold, the ECU doesn't lean out the fuel for warm/hot air the way it's designed to. The gizmo also is basically an O-2 sensor eliminitor, keeping the O-2 sensor curcuit in the open or closed (wish I could remember which it is) position all the time. The performance is kept high, NOT improved. You gain no horsepower or torque. It's only designed so that you don't LOSE any when conditions are not optimum for keeping emissions to mandated levels. You would do much better with a proper remap (ala tuneboy). Like it was stated above, too good to be true!