The AccessPORT is a handheld device that allows you to reprogram your vehicle's computer (ECU) to optimize parameters such as the air/fuel ratio and ignition timing. The "mapping" will also increase boost, remove the speed limiter, and more for instant performance results you can feel! However, the AccessPORT is so much MORE than just a REFLASH DEVICE. It allows you to monitor your Fuel Economy (average and real time), perform performance tests in order to estimate your 0-60mph and 1/4 mile time, read and decipher ECU trouble codes (CELs), and monitor live data via the OEM vehicle sensors which eliminates the need for costly aftermarket gauges.