hi paul,
The fault is defo fuel pressure related
start by replacing the fuel filter
its also possible for a blockage in the fuel lines or a faulty injector that can cause this error.
the fuel pump regulator or a fuel pump pressure fault are another reason.
As you can see there's many things that need to be ruled out.
Get the car onto a IDS that should pin point the exact cause,maybe worth using the main dealer for the IDS plug in because they will have factory up to date software installed.
A little expensive I know but it will defo pin point the fault,I take it you have only had it onto a code reader.
IDS machine is the next step
anyway m8 good luck with it and all the best.
paul
February 2012