Limp mode now and again

Hi about every 3/400m i get a error code of 4560 something to do with fuel rail pressure plausibility low, any ideas where to start car runs perfect, then goes into limp with amber engine light on, turn car off and it's perfect again, had BMW independent check it and says could be about 5 different items/ causes, would be nice to have a more detailed report, anyone had similar fault,
2008 cooper D psa 85k thanks in advance.