With my engine light on, I checked and am getting some codes in my INPA tool for my 2008 E70 3.0Si:

2C3E A1 Lambda probe in front of catalytic converter 2, control failure or cable transmission failure?
2CA7 A1 Lambda probe heating in front of catalytic converter 2
2C9D A4 output heater O2-sensor before catalyst bank2

So, definitely looks to be pre-cat Lamdba. I'm a pretty good DIY'er, but haven't replaced a probe yet. I read that the pre-cat ones are easier. Any links to good pics/description of what's involved would be helpful if anyone has them. How can I tell which one is bank 2?

I can't tell from this diagram if it's number 1 or 2 that I need.

I found both parts (Bosch) on Amazon. Part 1 is a generic description, where Part 2 has in the description name "Oxygen Sender PRE-Cat Rear Manifold".