Replaced the sensor. Reflashed a new map. 2 run cycles later and the car is running the best since dropping in the new engine. Both sensors are reading 0-1 degrees at idle like they should with my map. I noticed a Mitsubishi logo on the sensor.. that's the problem right there!
Anyway, idle is not as smooth as I'd like but it's much better. I'm hoping to dial in the cams some more but the manifold pressure is oscillating right now. I drove the car on the road for the first time with the new build, and it drives pretty well now!
Screen shot of idle right now. any thoughts? I think adjusting idle stability may help.