Hi all, a bit of advice please!

I have late 97 Passat 110Tdi and the car has suddenly (ie 2 days ago) started going into limp mode and throwing back the fault code 575 - the manifold pressure sensor. If I delete the code and drive very gently, the code does not return but as soon as I use any real throttle input, back to limp and the same code. Even though stored in the memory, it seems to come out of limp mode if I turn off the ignition then restart but as limp kicks in as soon as I use any real throttle input, I can't be sure.

I replaced all the vacuum pipes with silicon a few months back and have checked all these and all are fine. I have checked the VNT on the turbo is working - I don't have a vacuum pump but even sucking the pipe generated free movement of between 15/20mm. I have visually checked all related wiring that I can get to and there is no chafing/rubbing through to be seen.

After reading all the forums I could find last night (some rather conflicting advice out there!), I'm coming to the conclusion that the N75 valve is the next most likely candidate but I don't want to just go replacing this - lets just say things are a little too tight to be replacing components here, there and everywhere without a certain level of confidence they will sort the issue.

This car does have the pressure sensor at the back of the engine bay on the 2in hard plastic pipe (from the intercooler I think?) rather than the older version with the pressure sensor in the ECU.

So, the main questions: Does the pressure sensor itself ever present any problems or should I just bite the bullet and replace the N75? Or is there anything else anyone would suggest I try first?

Thanks all, your advice is much appreciated.
BadgerBoy