hi everyone.i was going to replace my n75 valve which i believe is the vw dump valve.i was wondering is a aftermarket one worth considering something like a bailey or forge?ive aloso heard of a n75j valve im not sure what this is tho.when i rang my local vw dealer up they said that it isnt call a n75.apparntly thats the fault code.any help would be gratefull...cherrs guys