As some people know, your vehicle is controlled by a computer, called engine control module (ECU). What it does it regulates the engine's timing, fuel distribution and emissions. By adding an after market performance chip (or also know as Superchip), one can set the Horsepower and/or it’s fuel distribution.
The reason for a performance chip is to improve a certain functions on a vehicle. Such as fuel efficiency and turbo boost, by replacing an existing chip with a modified, compatible chip.
When the performance chip is connected to your vehicle, it immediately detects the ECU settings and uses them regulate whatever functions it was programmed for. For instance, if it is supposed to improve fuel efficiency, it will receive signals from the fuel system, and the chip will adjust its settings to regulate all fuel issues.
Although performance chips are beneficial for enhancing certain vehicle functions, they also void any manufacturer warranties you have for your vehicle. This is mainly because the engine control unit (where the chip is installed) is a sensitive, computerized area, and any disruptions within it can cause engine failure.