If you're lugging under 1400 rpm in od with some of these 3.5 v6 gen3 taco's, they will sort of sputter, or shutter. Imo, it's a combination of a wonky transmission, and a sub par tuned engine. I keep hearing about this from a few others, but have yet to experience it in my 2020 v6 sr5 access cab which runs much like my gen1 4.7 tundra, just that the taco has more top end. Whatever was done during assembly on my tacoma that I had requested built in texas, it performs great, no complaints. Imo, it's just a crap shoot like other manufactures to get a very good vehicle, or an average to sub par build. Toyota has become more gm, and ford like every year....they're still better than those other guys, but they're not your grandpa's toyota anymore.