Just in case somebody is having the same problem, to make a long story short ,what fixed this code for me was replacing the post cat oxygen sensor Bank 2 Sensor 2 and I haven't even replaced the other post cat O2 sensor yet ,x5 is due anyway. Vehicle is 2005 X5 3.0 120,818. Original MAF,IACV,intact intake ,new fuel filter after reset and 200 miles mixed drive.
Hope this helps.