2005 ford V10 going open loop while driving

2005 F250 6.8 V10 6sp MT 70,350 miles.   This truck will go into closed loop normally. The upstream 02s count perfectly and fuel trims act normal as well. Not moving in the service bay..... run the rpm up to 2000 and the upstream 02s go full lean all the way to the basement and the STFT start subracting fuel. At the excact same time the fuel system goes open loop. After 30 count or so the system goes closed and the 02s start counting again. It will set a misfire on cylinder 6 when this happens. I have changed the plugs and all coils. It will also drop out of closed loop and do the same thing while driving at cruise speeds. I suspected a pvc problem due to oil conusmption so I plugged the PCV hose with no change.  Will a misfire cause a closed loop drop out? I have attached the scanner data at the time of the issue.

Some times the data pid for loop status in graphing mode is nice enough to expand to Closed Loop, Open Loop, Open Loop Driving (decel or clutch in) & Open Loop Fault.
Can you feel a misfire? It gets harder to tell the more cylinders are part of the engine. On a 4 cylinder, a single cylinder misfire takes away 1/4 of the contribution, very noticeable. On a V10, it's only 1/10th loss of contribution. Not as obvious.
My gut says chase the misfire.
I would not skip a compression test (relative or traditional, your choice), or a leak down test. I have seen valve issues and injector issues on this platform.
BTW, sounds like a cool truck. I have never driven a V10 mated to a manual transmission.
 
Cylinder 5 exhaust valve burnt causing slight to noticeable misfire on a 2005 Excursion stretch limo.

I do feel a misfire. I have a backstory finally on this truck. It popped #6 plug out and had to be rethreaded. I did a relative compression with my scan tool and #6 was low. I got the truck to go into a fit just by holding the throttle at 2 grand. While it was going full lean and running rough I had a vacuum gauge connected and it was steady at 18. Unplugged #6 coil and no change (still ran rough) I had to move on at this point. Ill try to get back to it in a couple days. Its seems odd to me that both banks go hard lean identically. I would assume that a misfire or a low compression issue on one bank would only affect one 02

I think you're seeing the effects of a transition to open loop, not a genuine lean condition. The relative compression test ID'ing #6 as low is enough for me to want to do a leak down test.

That is my next step. I will say that when those 02s are counting and working properly this truck runs perfect. It pulls good and idles smooth with no trouble codes. I can force it into retard mode by holding the throttle at 2 grand and it starts shaking and pushing everyone lean. Even with 2 upstream 02s going clear to the basement the STFT also goes negative. My brain says the fuel trims should be trying to add fuel not take it away. I will do a compression and leakdown next. Its almost like something is pulling a data line down.

Oh but fuel trim and 02 dont come into play in open loop. Im answering my own questions by reading my own questions. Helpful