I'd start by checking 1) the 3 fuel pumps on the left side of the motor and 2) VST filter inside the VST tank, same side and near the fuel pumps, and 3) O2 sensor cleaning.

In my experience, a dity O2 sensor usually results on loss of top end RPM's, but not stalling. Common causes for stalling are fuel pumps and VST filters. It can be other things, but these are the common ones I've seen. It's probably in your fuel delivery system somewhere since it occurs at higher RPM's and will restart after it stalls. My bet is either fuel pumps or the VST filter.