Dreaded errror 4530

[jvncorreia]

Well, bought a X5 35d 2010 with the mighty M57 engine a few weeks ago, has a few issues some have been fixed some are just weird like this error 4530. I'm calling it weir because sometimes is there with code and sometimes doens't give an error but I cant feel the low boost only after 2500rpm and never goes into limp mode. Since doing some research I have change the vacuum lanes, new seals to the vacuum pump and new electronic valve(11747810831). Sometimes I have low boost sometimes I dont and this is what is making all the information that I'm reading even more confusing, the fault is intermittent. If someone has gone trough the same problem and can shed some light would be really appreciated.