Two new OBDII port plug-in modules for 2005+ GM vehicles equipped with Active Fuel Management (AFM) which drops cylinders and reduces power are now available from DiabloSport. The Sprint Module disables the factory AFM feature for maximum power and performance and allows vehicles to stay in V8 mode at all times without having to reprogram or reflash the ECU! Meanwhile, the Marathon Module improves fuel mileage by allowing V8 engines to behave like 4-cylinder engines when cruising, yet still retain full V8-power on demand. The module saves fuel by allowing the vehicle to stay in 4-cylinder mode for 80% of the time, rather than 35% of the time as designed by the factory.