I've done a bit of research and think my error code and low boost are separate issues. I'm also getting low mpg ~25. Which is the same as my 1991 Porsche 944 S2, which is a 3.0 l straight 4. So something must be wrong.
A friend of mine also came over with his Octavia VRS last night and we put them head to head. His was quite a lot faster. i.e. at 80mph from standstill there was probably a 10 car gap.
I've done a bit of reading and think the low boost may be caused by the diverter valve, or the PCV as the link above explains.
The P0441 is probably caused by the vent/purge valve.