Hello all. Can anyone shed some light on the N75 valve. I have been through the forum but not really got an answer (or at least an answer I can understand!). Anyhow, I am running a standard 1.8T - does changing this valve achieve anything, or does it only achieve when the car has been chipped, re-mapped, etc?

Appreciate any advice you can give me - in numpty language please! Thanks alot. Dave.