Thank you.
I am not sure I have ruled out a vacuum leak - only that all hoses that I can see and think are vacuum lines look OK to me. Recent CCV replacement, cold climate.
within the the afternoon, I reset the error. Swapped the spark plugs and coils from 1-2-3 to 4-5-6 and error returned once again P1191 bank 2.
My mind I was thinking its too much fuel, always associated "rich" with fuel but DUHH...its the "oxygen" sensor reporting.....

Is there any tests for vacuum leaks?

My error sometimes stays off for several days/trips and they sometimes returns quickly (2 short trips) usually just as car is at warmed up temp (between cold/hot on the gauge). It may be returning quicker when the gas tank is full.

I am very much an amateur and stumble through and sometimes rely on my own misguided logic rather than knowledge. I am scared thats its a major valve/cylinder issue because it keeps coming up only in bank 2.

Any possible chance it could be as simple as an air filter? Just looked up when I replaced it about 30,000 miles its an off brand (looks fine).

THANKS!

__________________
2004, X5, 3.0, 202k+