SCT Performance ECU PCM Flash Programmers / Tuners are an essential tool for increasing horsepower & torque for your American car or truck. These easy-to-use handheld devices connect to your OBDII port and allow you to adjust parameters such as axle ratio, speedometer calibration, tire size, transmission shift firmness, transmission shift points, global rpm spark, pedal response, idle adjust, mass air flow meter / sensor (MAF), speed limiter / governor, DOD (Displacement on Demand), fan control, air intake (disable check engine light), rev limiter, traction control, TPMS (tire pressure monitoring system), and much more. Pre-loaded tunes are included for most Ford, Chevrolet, GMC, Cadillac, Dodge, RAM, Lincoln, Mercury & Jeep vehicles. Custom tunes are also supported. SCT's DYNO Proven tune files will unlock new levels of power and acceleration. Use SCT's devices to monitor your engine parameters, read & clear DTC's (diagnostic codes), and tune your engine for maximum power output or optimal fuel economy. Gas & Diesel vehicles are supported. For gas vehicles, each tune is based on different fuel octane levels (87, 91, 93).