Hiya mools,
Thanks for your reply.
I'll post a link and an image to try and better demonstrate which bit of pipe I was referring to.
The part
here shows the metal tube between the two rubber/silicon hoses. Any Td5 owner who's spent some time under the bonnet will have looked at the proximity of this pipe to the serpentine belt and said "Sheesh, that's pretty close to that". IIRC the flat spot on the pipe is there to minimise the lilelihood of the two parts making contact.
So, this metal tube could have the turbo pressure sensor tapped into it but it is actually not that thick. There would not be sufficient thread to stabilise the sensor for my liking.