Our truck is stalling on us while driving, but only sometimes

We are currently thoroughly confused. Our truck is stalling on us while driving, but only sometimes. It only happens when the truck has either been running for a while, or it's really hot outside. She starts chugging like she's not getting any gas. Stop and let her rest and cool for 10 minutes, and sometimes she will be fine, other times she does it again after a few minutes. The more we press the gas pedal, the more trouble she has. If we barely press the pedal, she will chug on that way for quite a long time, or she will even out.

We emptied the gas tank, which included a standing inch and a half of water. We've already had to replace four catalytic converters, eight spark plugs, and cooling fan. Ignition coils, and bank 1 o2 sensors test fine. We already know the heaters on our bank 2 sensors are bad, and the fuel filter and sending sensor are good as well. There are no coolant leaks either. We are currently saving for replacement of piston rings and valve guide seals as she is burning oil pretty badly. However, there is almost no pooling of oil in the spark plug wells. We do still have the smoke and smell when she starts up most of the time. We've started a regiment of throttle body and carburetor cleaning, with noticeable decrease of the sludge and grime in combustion chamber and cylinders.

The air intake has been running high, and we've considered swapping it out for an open filters design to help keep her cool. The cooling fan and sending unit were replaced under recall several years ago supposedly. The only DTCs we are getting are for the O2 sensor heater B2S2, and the Catalyst system efficiency below threshold (p0051, p1168, and p0420). We've been told she may be stuck in fail-safe mode since it took so long to figure out the catalytic converters had gone bad. One was empty when we pulled it down! Any advice would be great. We do our own mechanic work since there's no one around, and we are losing faith we will ever figure it out.