Parr are always working with suppliers to try and overcome customer issues with their cars. This clever device manufactured by Cargraphic is one such example. The latest generation of Porsche models with switchable sports exhausts have an active valve control system which will close exhaust valves in certain scenarios, even if you request them to be open. To address this Parr can offer a range of exhaust valve controllers to put the driver back in charge of what the valves are doing. The controllers can be fitted and removed without any modifications to the wiring harness on the car.