Tranny or Motor missing at high speeds

Hello all ! Quick question. My 2015 4x4 Tacoma with 255,000 miles is acting up. While doing around 60-65 mph on the freeway if I accelerate harder to climb a hill the motor or tranny starts hesitating for a bit then stops. Can’t tell if it’s the tranny or the engine missing. Toyota couldn’t find any issues with the transmission. No engine codes either. I changed the air cleaner filter and will change the plugs tomorrow. Thanks for any help in advance!!!
Robert. Petaluma Ca

 

Without knowing the maintenance history and with the miles on it, my first guess would be the fuel pump.

 

Thank you for the response. I basically change the oil every 5k and it’s only had the maintenance that came with the warranty. After that I’ve only myself changed all the gear oils. Changed the serpentine belt and that’s about it. Maybe even the fuel filter might be the issue? Which has never been changed either. Transmission had a flush at 200K and I just hit 255,900k.
Your suggestion is much appreciated!

 

Wouldn’t that throw an engine light warning? Just wondering!

 

I don't believe these trucks come with a fuel filter. I think it's some type of screen in the tank.