Edit- Just wanted to note I gave the wrong code in the original post.
Vacuum is great (-10psi @ idle), pressurized the intake manifold and it held very well.
I think you read it wrong -- maybe I said it wrong -- everything WOT is great except HIGHWAY speed cruising.
Literally cruise control set above 70MPH will eventually first disable cruise control (cruise light willl start flashing) and if I don't slow down, the AFR (on the COBB, have an AEM UEGO in the box but not installed yet) reads 20.3, and stays there. It seems to not *actually* be lean, but then it goes ahead and will throw P1153 -- O2 Sensor Curitcut Range/Performance (High) (Bank 1 / Sensor 1) -- which is a brand new sensor.
I just went out again to duplicate it for the COBB guys. Drove around town, it was fine. Pulled on the highway, WOT 1, 2, 3, everything is fine -- hit 65 ish, put it in 6th gear, put the cruise control on -- and then eased it up a mph as I went until I hit 70. About a minute into being around 70 mph, the AFR's began to creep from 14.7 to 15.5, 16, 17, 18, then 20.3 - stayed there, and then code.
Honestly, this only happens with highway driving. I'm baffled.