Fuel issues

Fuel pressure regulation, air flow meter issue, internal engine issues, the list is too long to go into here, have the BMW service provider you use start with the easy stuff like state of tune and checking the basic stuff like what I have mentioned and look at the possibility of an engine wiring harness short at the point where it is in contact with the fuel rail. Also the ECT might be on the blink, like I said, start with the easy stuff.