The AFR Plus or GEN 4 by Dobeck Performance brings together two technologies within one system to make it the most powerful, user-friendly tuning device on the market. AFR Plus combines an EFI controller with a wideband O2 sensor and AFR gauge to provide a user instant fuel trimming ability and feedback about their vehicle’s tuning operation. The GEN 4 is a piggy-back EFI controller because it does not replace the stock ECU, but rather monitors the signals to the injectors and makes fuel adjustments based on the mode settings. The GEN 4 has a push button interface on the gauge allowing access up to 6 different modes to allow for quick fine tuning by the end user without needing a computer. Please give us a call if you have any installation or technical questions regarding the controller.