The VP12 is a vehicle specific, custom programmed 20MHz Microcontroller. It utilizes its high speed serial input/output to communicate directly with the ECU through the OBD-II port. Inside your ECU is a 3-dimensional table of values called a map. This table tells your fuel injectors exactly how much fuel to deliver given current air temperature, density, engine speed, throttle position, and other variables. From the factory, this map is generic and designed to provide a sluggish, no-surprises style of driving to suit a wide range of drivers. The VP12 temporarily replaces parts of this map with parts from our highly tuned performance maps, and will safely unleash you engine's full potential, without voiding the warranty.