2020 with 100k miles, cleaned the throttle body intake and holy crap did that make a difference

I thought I was having transmission issues. It really felt like when I was accelerating from a stop the van would hesitate for a second like the transmission was slipping then catching. It was really bad if you slowed down, didn't come to a stop, then accelerated again. Like if you slowed down to go over a dip then accelerated, it was really rough.

I got an oil change on Friday, they recommended cleaning the TBI. I declined the service and just did it myself. Took less than half an hour, and the van now feels perfect when accelerating.

The issue was not a slipping transmission like I thought, it was the throttle body sticking, and the engine kind of surging when I accelerated.