Traditionally car engines tuning involved replacing the engine parts with aftermarket parts that offer better performance. These days the game has changed a lot. Even though engine tuning still requires the replacing of a few parts, most of it is about the programming of the onboard computer. The onboard diagnostic tool can tell us everything about the current configuration and performance of the car. Also, the problems with the car, if any. By manipulating the configurations of this computer, we can hugely increase the performance of the car.