[Pruzina]

Hey would like some help.
I have 05 645ci. Getting bank 2 catalytic code. During driveshaft service I found that my bank 2 catalytic is completely missing internals. bank 1 is ok.

Question 1 did someone attempted bank 2 cat replacement while engine in car. I can imagine that if it's possible it will be major pain in the ass.

Question 2 does anyone knows if cat from 650i, 550i or 750i would work? realoem shows different part numbers but as it's essentially pretty similar engine it may maybe work.
What do you guys think.

thanks