RPM Drop when shifting to drive or reverse

Hi everyone

I have a 2001 tacoma xtracab 2.4L with automatic transmission ( A44D )

Even Though the engine run nicely on idle, I have some issues with the performance of the engine and transmission.

1. When is in Park position the RPM are at 950 (It doesn't matter if the engine is cold or hot.)

2. When I shift to drive or reverse the RPM drop to 600 to 750 (cold engine)

3.When I shift to drive or reverse the RPM drop to 450 or less, sometimes engine dies (this happen when the engine has reached high temperaturas)

What I did:

-I cleaned TB, IAC valve, maf sensor, fuel inyectors.
-I changed fuel filter, air filter, spark plugs, engine oil, oil filter, transmission oil (two times), radiator coolant.
-All vacuum lines look good.

Can the transmission cause the RPM drops if so what would make it do that?
My transmission has 264,000 miles

What do you think should I do?

Thanks

 

Air intake hose good from engine to maf sensor by air cleaner box?

 

any codes? Start with the simple things

 

Thank you Mechanicjon, I will check the hose

 

It's weird because it doesn't have any code.

 

When was the last transmission fluid change? What does your current fluid look like?