slow down devon,,,
in the EGR assemly there is said valve AND the anti-shudder valve.
The antishudder is basically an air choke system that is used on engine turnoff. When I was changing the vac hoses on my car, I managed to break the nipple at the end of the black mushroom thing which is near the EGR. That is the anti-shudder valve actuator [also controlled by the N18]. On every engine turn off I got the car shaking like los angeles during earthquakes,,, not that good for the engine mounts,,,
Now, I've heard some don't have this prob and on dieselgeek they sell the so cal racepipe which is a straight pipe instead of the EGR [so basically the thing from you took the idea off
] so it must work on some tdi's,,, but I don't know on which,,, on mine it deffo didn't!!
If I was you I'd [carefully] disconnect the vac pipe at the end of the antishudder actuator and see what it is like on engine turn off,,, lemme know then,,,