P1093 2006 X5 suggestions?

[mendes9]

Hello, looking for suggestions on a P1093. I'm a DIY mechanic, with some knowledge. Yes, I've searched for this code on many forums. A little history and then my diagnosis. P1093 is a rich condition for Bank 2.

1) Car has 196K miles, the only recent change of any kind before this code popped and goes away sometimes was change in oil type to Valvoline 5W30 restore and protect (3,000 miles using this oil).
2) Code does go and come, but seems to be staying on more recently.
3) I have autel mk808 and ISTA, used these scanners, and I can see why it's throwing the code.
4) All oxygen sensors appear to be responding fine. I have replaced Bank 2 downstream oxygen sensor just in case, which didn't make a difference.
5) About the pic below, graphs are for S1B1, S2B1, S2B2 (I do show the value for S1B2 .77 volts). Autel scanners unlike launch can't show a bunch of multiple individual graphs, and on my mk808 I can only show 3.
6) The graph shows that S2B2 oscillating, and S1B2 (highlight with .77 volts) is always steady. S2B2, when not isolating will also be very low like .1 or .2 volts indicating lean. So as you can see since S2B2 is reporting lean the DME is pouring more fuel, look at the top graph S1B1, vs the 2nd graph S2B2, S2B2 graph has much level saw tooth graphs, hence the code.
7) So why does the code sometimes go away? In graphing this for example, sometimes I will raise the RPM to 3,000 and then all the sudden the S2B2 voltage matches S1B2 and acts completely normal. This is what's baffling.
8) From the data it suggests a failing catalytic convertor on Bank 2 since it's oscillating, but what has me going is that why wouldn't it be constant. Again, in testing yesterday if I raise RPM to 3, 4K rpm then it's normal.


What I've tried:
1) Replaced downstream Bank 2 O2 sensor, no change.
2) I've seen other posts claiming to solve this and other never solving it (one person gone so far as to re-program the DME not to run this test). I've smoked tested from intake and from rear tail pipe. There are no leaks on intake and no leaks on the exhaust before downstream O2 sensor.
3) Rest adaptations, I've seen posts on where the resolved it didn't work here.
4) I may do an injector drop test to see if maybe I have some leaking injectors but the data doesn't suggest that to be the issue, the data shows a lean condition on the downstream O2 hence the computer is pouring more fuel.
5) I've seen other posts where swapping down stream, or upstream sensors, not sure about that or how that could help unless they were wrong and mine are not, again 196K and these are the 2nd set of O2 sensors replaced originals at 100K (Bosch OE BMW)

Any suggestions would be appreciated as a catalytic converter on this car may be a death sentence and I really enjoy the car.