1.2 Ibiza FR error codes

[ash1872]

Hi

My 62 plate Ibiza FR is going in to limp mode with the engine management light also displaying. The following errors are coming back:

6229 / error code org: P0088000
fuel system pressure
pressure too high

11824 / error code org: P334B00
boost pressure regulator
incorrect function

16715 / error code org: P065300
reference voltage, sensor B
signal too high

Any ideas as to what's causing this?

Thanks in advance.