Fabia VRS with no/intermittent boost

Hi,

I've done some searching on here, but can't seem to find the definitive answer to my problem.

I have a 53 plate VRS PD130 totally standard with 125k.

Had engine coolant temp sensor problem - wiring, now fixed.

Showing fault code 17552 intermittent.

I've changed the MAF sensor but no improvement. I've also traced the wiring and have continuity between the MAF Sensor socket and the Diesel Injection Control Unit. I am only getting about 8.5 volts at the power line (Black and yellow connected to battery circuit).

Does anyone know what the supply voltage to the MAF sensor should be?

I've disconnected the MAF sensor and have the same driving response as when the boost is not working (limp mode). as I said this is intermittent. It seems to rectify itself on wet days.

I'm located in Bathgate, so anyone local with a VAGCOM your help would be appreciated.

Do you think its likely to be a N75 issue? or a faulty MAF sensor? (bearing in mind I just changed it)

This has really got me stumped, and there doesn't seem to be any detailed information on how to get to the bottom of this problem.

cheers

C