I have a 99 quattro which has only done just over a hundred thousand miles, the car has a very annoying loss of power around 3000rpm through all gears, i seem to get the power back as quick as it goes, there is a dump valve on the car and i can hear the pressure release at the very point (3000) then feel the power back right away??? scratching my head with it.

Also i recently had a new down pipe fitted and since this the new down pipe seems to rest on the crossmember causing a knock when changing gears and when the engine is started, thanks in advance :) 

Dump valves often don't work that well if the car isn't designed to have an atmospheric valve fitted... could be that causing it?

Yea I was thinking it could be that, the valve was on the car when I got it, not something I would choose to do so I'll be putting it back to original and hopefully it will solve the issue :)

Let us know if it turns out to be the dump valve. Could be useful for other members to know if they were thinking of doing it!

Old post but it sounds like the N249 dumping boost. Scan is required.. May well be n75 issues.