I'm not sure what is wrong

When was the last oil change on it?

 

OP, the first thing you should always do when buying a used vehicle with that high mileage especially if its not from a large dealership, is do routine maintenance. Plugs, oil, filter, even coolant. I would add MAF/TB cleaning to the list.
Lastly,, scan for codes as suggested since failing O2 sensors / cat can cause power loss or hesitation.

 

The rattle could be heat shields, skid plates, loose bolts, or even brake pads.

Traction control kicking on when you're on the gas coming out of a turn cutting power?

 

If the traction control issue is the problem, try turning off your traction control and drive it around a little. See if the problem with acceleration continues.

 

Not a lot to go on in the video, but I heard a loose heat shield. Get under the truck and check it out. No mechanical experience necessary. Follow the exhaust from the engine and try to wiggle the sheet metal shield.

 

I have a bit of rattle when I accelerate but have found it to just be my exhaust pipe. Are you sure that's not it?

 

Also OP, you should edit the title of your thread. "Help!" is usually reserved for people stuck or disabled out in the wild, like an emergency.

 

So, an update: still not sure what’s wrong… I did find out that the rattle is only at 1.5 rpm. However there is a new issue that has been developing recently with the power cutting. I’m guessing it may be wiring or brake related but I’m not sure.
Power cutting/searching for gears maybe? happens after turns, and randomly at highway speeds. Sometimes feels like engine breaking, like it shifts down and I have to step really hard on the pedal then Rpms go way up and then back to normal. I have had some brake light issues where the brake lights will randomly come on, and turn off when I mess with the pedal a little. I’m kinda concerned that I’ll get into a wreck cause it just sits there for a couple seconds. Still have no clue what’s really wrong but I’ve got some more info. Thanks to all who have tried to help.

 

Well.....I'm completely lost with the description of the symptoms.

Especially the 1.5 rpm, I didn't know that was possible.

This is Friday...............

 

was it bad cell in battery?

 

This sounds like a slipping transmission.

 

most modern cars when brakes come on the ECM/TCM unlocks the torque converter so if you have brake lights sticking on, you need to address that first, before diving into transmission issues. brake switch should be a cheap easy repair

 

MIGHT have your solution..
I just fixed this sound/issue on my 200,000 mile 4cyl....For me the exhaust gasket off the manifold had rotted out along with one of the spring bolts that holds it shut. When you give it gas it forces exhaust down the manifold to the pipe but the lack of a gasket/bolt causes it to immediately exit and rattle like a bastard...

Take a look and see if that's what it is...
Here is my post with pictures...
https://www.tacomaworld.com/threads...ment-on-a-2nd-gen-2-7l-4cyl-with-pics.730328/


This is where the leak was...

 

Hmmm...
also, have you disconnected your battery for an hour to let the computer reset?
Just another thought...

 

Thank you guys for your help, I have solved the break issue, but the rattle is still there. I have a good lead on what it is and hopefully it'll get fixed soon!