2020 TRD sputtering...

like others said, 3rd owner in that low of miles, seems really really unusual... personally I would have passed. Second, it sounds like you may be in too high of a gear for the speed.

 

It could be just normal as some of these 3.5 just don't perform as well as others with the same tune. A buddies tacoma was proof of that, now he's grinning ear to ear with his newer frontier.

 

Did you have a chance to drive your buddies frontier?

 

I never personally drove it, but went on fishing trips enough times in it to see that his truck had acquired some weird stuff my truck never, and still won't do like his did. You'd be doing 45-50 mph up a slight incline on the highway, and his truck would be stuttering, or bucking throughout the cab. He always said it happens at 1200-1400 rpm while the truck was traveling in od. We did roll on runs down a vacant dry dam road starting side by side. We'd both nail it, with my truck taking an instant lead, and just pulling away. I heard the same from a buddy that works for our water company which has a fleet of these gen3 sr5 v6 auto's....he claims some just make more hp than others. The water company has been slowly switching over to rangers, so we'll see how that goes
As far as driving his frontier, no, but ridden in it. It's a nice truck that rides more compliant than my sr5. Very smooth linear power with just as much or more down low. I can see him liking it more than his 2019 tacoma, but I'm not ready to jump ship yet.

 

Remove and clean the spark plugs.
Clean the throttle body.
Clean the Mass Airflow Sensor.

These are but a start.

 

It's a stick...I have 15 years driving 13 speed semi trucks...