RENNtech EVM | Exhaust Valve Module | 190-AMG GT SeriesRENNtech Exhaust Valve Module Permanently Open Exhaust Flaps. 190 AMG GT Series. AMG GT GT S GT C GT R GT Pro BS EVM Exhaust Valve Module (Remote Controlled) NOT SO FUN FACT: If your Mercedes AMG is equipped with factory exhaust valves, with or without a center console button to open or close them, factory settings do NOT allow the flaps to fully open unless certain speed and or RPM have been reached. For example, while cruising the exhaust flaps will