P0171 and P0174 related to transmission on a 2nd Gen Tacoma?

I just got a 2nd Gen Tacoma from my dad. It's family owned. It's a 2010 PreRunner Automatic Transmission 4.0L V6. My pawpaw bought it brand new. He had never had a automatic truck before, so he was towing coon skin and fur for his fur company and was in the wrong gear, my father got it after he passed and noticed it doesn't want to get out of third gear automatically and it starts reving if u try to go faster but it doesn't, so u have to manually put it in 4th gear to get it to shift after third gear. Which is weird because this is a automatic. However, just sometimes when I'm driving it'll shift normally, but most of the time it doesn't. Check engine light is always on after getting new battery, maf sensor, there is no vacuum leaks, nor any damage to the fuel pump or system. But I was told by a mechanic, if the transmission is having problems it can trigger O2 Sensors and make the ECU run lean or rich, in this case Im not sure. Bc everyone else says the P0171 and P0174 is for fuel and airflow problems, but there's not lol, sorry for the essay but I just want opinions before I get this trans rebuilt lol
But it's been driven like this since 2014 from what I'm aware of. She still drives she's beautiful Point A to Point B. My first vehicle, don't have to be perfect but that is literally only problem lol
And here is what it looks like
Oh and those are 20" Toyota OEM wheels lol. Which I couldn't believe at first

 

Lean codes can not be caused by a transmission issue however an engine that is running lean can cause it to not want to upshift because if it's not running properly you end up giving it more throttle to make it go so the transmission will want to shift at a higher RPM because the throttle is open more.

My first question would be is if the intake is stock or not, aftermarket intakes can skew the MAF sensor signal because the sensor is calibrated to the stock diameter MAF housing and airflow characteristics.

Beyond that we need to look at fuel trims, AFR, and O2 sensors over various RPMs and loads to determine the type of lean condition, how lean it is, and if it's in fuel control or not.

 

Good morning y'all, about to go get what I call a "P0174 and P0171 kit", seafoam, diagnostic scan tool that can access live data, a cigar and a fluid pump, a MAF sensor, and air filter oh and I figured out it also had P0300 that comes and goes. Wish me luck. Tacoma 4 LIF3

 

We need to address the lean condition first as the misfire is most likely an effect of the lean condition.

 

It was the that old ass reusable hard filter that was in it, it was so brittle pieces break by touch.
Check engine turned off when I put a new one in it

 

wheels actually look nice...

 

Thank you sir appreciate it yet. Got them polished 100miles ago.
I can't believe it fits 265 50 r20 on a stock suspension but it was already factory lifted a few inches