I cleaned the TB really well about 15K miles ago. And yesterday when I was looking for vacuum leaks I took the intake hose off the throttle body and it was mirror clean. No carbon build-up at all.
I don't have that scan tool. Plan on getting one later down the road.
I already purchased new Throttle Body, should have it on Monday. Really hope that will be it.

 

I replaced a throttle body last night.
It didn't do a thing, sadly.
I read online that some guys had some good experience with cleaning/replacing MAP sensor and O2 sensors.
Will try that and post the update.