[bshambam]

I double checked the nuts and bolts on the intake manifold side to make sure there wasn't a leak.

I also took off the MAF sensor and cleaned it with sensor spray.

I disconnected and reconnected the battery, and connected carista.
It looks like bank 2 post cat o2 sensor is reading an error...

So it looks like whilst driving in anger, something got loose on the exhaust side.
This will explain the bog, and it may explain the jumpy idle, as well as me seeing some exhaust ploom moving out of the hood during the weekend drive.