Yea sum1 said its on the diesels only. What happens if u unplug the n75 boost control valve? I did this n got no difrence, is tht rite? Also, where the pipe comes off the top of the n75, and dwn into what im asuming is the wastegate, thers a bar coming from that, leading into the exhaust area, im assuming this opens n closes something, could that be stuck? Lol. Looks abit rusty. Im jus guessing now haha.*
You've covered just about all of the bases,the 1 thing that stands out now is that un-plugging the N75 valve changes nothing! that means that its not working or your in constant limp mode. You could swap N75's with someone else to rule it out,it might be worth taking off the turbo intake pipe and checking that the turbo spins freely and does not have any/much play in it (free of charge that one) Limp mode should mean fault codes so its looking like N75 or turbo from the info above.
