Any chance the replacement was faulty too? (I've had used parts DOA on me).

Also, where are you located? If you're local, I'd be happy to try to diagnose it with you.

Check your plug that connects the TPS. Heat under the hood might be warping it... causing a loss of connection? I've seen that before.

Bend the contacts until they are sung...

I'm in San Diego. Yeah I thought of that too but this guy has a 5 star rating on eBay so I doubt it... Never know though

Good idea there too...

Hey duke808 sorry this one is really getting to you. I, also would offer help troubleshooting your components if I was nearer to you.
Is it possible to check for fuel pressure? Go over your ground connections making sure they are clean and tight?
Hate for you to dump a 4runner because of what's happening.

Have you disconnected the battery to reset any tuning issues? (I doubt this is the issue). You might want to give it a tune up as well.

hey guys yeah, I have been having my mechanic who predominately works on european cars do all the work on this thing since he's my main mechanic and does everything cheap. when I bought this he said he works on them too, and he's at a loss at this point. I'm thinking i'll take it to a japanese shop. I am not a DIY'er other than brakes and oil changes. I have had a lot of work done to this thing.

The unfortunate thing is it only happens in 85+ degree weather with AC on.... "winter" in CA is nearing and will no longer be those temps, so there really is no replicating this issue until next summer. It sucks. I guess I will drive my other car until next summer and let this damn thing sit until I can have a mechanic replicate. this issue aside, i've put a lot of $ into it and it runs perfect, also a socal car its whole life so zero rust. would be a shame to dump, I agree.

Have you tried testing the MAF against the OEM specs? You could also try swapping one. I wonder if yours is so out of whack that it has an abnormal air reading and wanting to go into a limp mode.

There's not that many components that'll cause an issue like this and worse case you could hand grenade the problem to solve it with a few parts from a junkyard.\

Likewise I'm in San Diego so if you want PM me and I'll see if I can give you a hand.

The throttle body is only the 1 part of the system. The other part is the accelerator peddle assembly itself. It has a sensor (rheostat) on it too. Im only locating a peddle assembly (78120-35401).
Could it be the cold air from the ac is somehow making that part malfunction?

I’m not necessarily sure that the ac really has anything to do with the problem besides the fact it’s placing an additional load on the engine.