Stutter on acceleration

2000 limited 4runner 270k. Drove home from work one day in the rain and hit a few big puddles, no big deal. Later in the day I went to go to the store and was met with a hesitation when I pressed the gas. It only happened when it was warm, but if I pinned the throttle the rpms would shoot up and I would regain power when it downshifted. It's acting as if it's not getting spark or fuel on lower rpms. Not very car savvy myself but don't have the money to have someone else fix. Looking at other posts I've seen that it could be plugs, wires, fuel filter, ECU, TPS, intake, MAF, etc. I changed my plugs about 20k miles ago, fuel filter was replaced a couple years ago along with the pump and tank being cleaned out, air filter looks brand new after maybe 6 months. CEL is on but for a knock sensor and it's been that way for years, I've been told to ignore it because it's faulty. How do I rule out each individual problem to come to a solution? Any info or help is greatly appreciated.

 

Check for new codes. But very possibly a bad TPS. You drive 90% of the time with the throttle in one spot and that one spot in the TPS wears out.

A slight hesitation could be from a spark issue. I had really bad plugs and I would get a small "hitch" in my acceleration. But not a big hesitation.

I don't think fuel since you can rev it out and it idles ok.

My big hesitation when going from a standstill was caused by my worn Throttle Body. I replaced the whole thing...but it was either my TPS or my Pedal Position sensor. I don't think you have the Pedal Position Sensor. So TPS would be my first go-to.

Get ONLY TOYOTA or DENSO parts.

 

I assume you are in "D" drive? Have you tried 4S as switching to "S" seems to change the torque converter lock up pattern and the VCS throttle profile. At least my 2017 SR5 acts that way. When I drive from stopped and go through a bump - like leaving a driveway and entering roadway and crossing the road gutter that compresses front suspension and bumps the vehicle- I get the momentary engine power loss. Driving in 4S instead of "D" seems to minimize the power loss. Turning off your VCS would change that feature which also causes a power cut back?