xDrive50i, P0641, and misfires...

[zowwiewowwie]

Hey everyone. Long time lurker, first time poster. Vehicle in question is a '13 X5 xDrive50i with around 115K miles on the SAV but only about 45K on the motor (it was replaced under warranty).

Recently got a misfire code for cylinder #7. Coil and plug were replaced. Following that there was a rough idle and a few miles down the road it started shuttering again. Ended up with codes for cylinder #5 misfire (P0305), Bank #1 too rich (P0172), and sensor reference voltage A circuit/open (P0641).

Swapped the #5 coil/plug (suspected bad) to cylinder #7 (just replaced/known good), cleared the codes and fired it up. Now I'm sitting with cylinder #5 misfire and cylinder #6 misfire. Didn't let it run very long or it may have gotten the P0641 again, I'm not sure. In any case, the fault did not follow the plug/coil so I am doubting that it is the problem.

Other items that may be of note. The short term fuel trim on Bank 1 is way higher than Bank 2 (20-25% vice -3%) and the Bank 1 cat temps were 200-300F cooler than Bank 2.

Thoughts?