The main purpose of performance chips is to improve the performance and fuel efficiency of the vehicle. The chip is the advanced technology that makes it possible to control many aspects of engine's operation. Connected to your car, the chip immediately receives data from the variety of sensors including oxygen, mass airflow, and manifold absolute pressure sensors, air temperature, throttle or pedal position to name a few. The most common way to upgrade the ECU (electronic control unit) is to use plug-in performance chip. It tells the data to your engine's computer and, if programmed right, gives your vehicle more power reducing fuel consumption. A poorly tuned ECU can result in decreased performance and driveability, and may even cause the damage of the engine.