thanks,
Yes, my car is not holding pressure as it should.
So, I assumed an injector leak - so I pulled the injectors and sat them on a towel with pressure and observed no fuel. Then I changed the regulator/filter (twice) and changed the fuel pump. So then again I had to assume I have a leaky injector (maybe it holds but leaks after its fired and doesn't quickly shut off??). So I switched injectors from bank 1 to bank 2 and my error did not migrate.

Appreciate all the suggestions/info you all are giving.

No garage and Boston winter weather - no fun fiddling around under the hood.
Reading about the Secondary air pump, I think I need to look that over? Does it pump air into the banks separately?

No, secondary air pump applies to both banks. Secondary air pump works when engine is cold for about a minute or so to heat up the cats faster so the engine goes to closed loop sooner.

Injector(s) could be sticking open some of the time but that pressure drop is awfully fast to be an injector and you aren't showing a cylinder misfire code.

Another thought I had (lately a lot of "middle of the night thoughts".
I replaced only the pump and reused the sending unit. There is a clear plastic accordion tube from the pump to the cover. I did not see any cracks or holes but I did not test it for pressure. If there was a hole in that tube, YES fuel would leak on the outbound as well, but it would just spray back into
the tank and I think our pumps pump at a greater pressure than required by the fuel rail? So in this theory, I could lose my prime if that tube leaked before The check valve of the pump yet it supplies the required pressure to run the car. But I still think my fuel issue is separate from trim issue.

Am I correct that running "rich" Will prematurely use up the catalytic converters lifespan?

Thanks!

Problems could well be unconnected but I would find the cause of the bleed down before doing anything more to address the stumbling.

Fuel pressure is controlled by fuel pressure regulator which would not be in the mix when the pump is off.

Yes, running rich can shorten life of cats but it would take a very rich condition for a long period of time. Cats get very hot and would burn off the majority of unburned fuel.

If your fuel pressure stays normal while engine is running for 5-10 minutes pump is working normally. I would block the return line, turn the key on to get pressure to normal and then turn the key off to see if it holds pressure. If it does that means the problem is on the other side.

Might be worthwhile to get a propane tank and the heater element that attaches. They put out an amazing amount of heat. Not expensive.

Thanks.
HATE pulling down the pan over the fuel filter. Can I block the return under the back seat behind the driver?

I changed the 4 cats about 4 days before the car was at a body shop
For 6 weeks (and I don't even know what shop - it was farmed out). Issue started shorty after I got the car back. First time I checked codes when the car returned, there were crazy multiple misfires. I cleared them all, my first thought was maybe the battery went dead and the car had trouble restarting. I HATE thinking like this, but.....my MAF or even my DME could have been swapped out with know problematic ones when the car was out of my possession. Although if you were looking for electronic parts- probably wouldn't take them from a 192k mile car??!!

That's why I stated in another post on fuel pump that it is better to pay the extra 20 bucks for the entire assembly and not fart around with switching out the fuel pump.

https://xoutpost.com/1084572-post13.html

Doesn't matter where you block it off, can do under hood if easier.

Anything that was swapped out would have to be a part that only causes a problem on bank 2.

There is a return under the hood??

Nope the return is with the fuel filter. Just like the regulator is no longer on the fuel rail, but built into the fuel filter. Careful with pinching off some of the lines because some of the line are hard plastic and if you try to pinch them, you will just crack them.

Back to my Original P code:
With my computer and BMW software DIS (or is it SSS?) my error code is P1191 and then it says - Trimming, oxygen sensor before cat, bank 2 ---too rich
with my iPhone app generic reader I get the code P1093

Just found this (about code P1191):
if the rear O2 sensor doesn’t agree with the front sensor. The most common problem that I have found with that code, is a air leak in the exhaust system. Normally at the flange were the converter bolts to the exhaust pipe. The leaks in that area do not let exhaust out. They suck in air. This give the back O2 sensor a false lean signal.

MY Flange is a MESS and one nut on bank 2 is totally rusted away.
Looked on RealOEM.com and they sell the bolts/nuts but it looks like the originals bolts are tacked to the flange of the headers? I am going to start another thread to see how others tackled removal of those bolts

THANKS!