06 Tacoma 2.7 4X4 randon misfire, higih idle on initial startup, and between 4th and 5th gears

I am at wits end with this thing. Has been in garage for months on end and no one can figure out because it will not throw a code.

-random misfire at 1/8-1/4 throttle
-Occasional stumble on take off
-idles very high 2k on initial startup after being parked for a few hours
-rpms will not drop when shifting from 4th to 5th gears unless you hold clustch in no throttle for about 10-15 seconds.

Toyota doesn't want to touch it since it will not throw a code.

Other mechanic who had it for 3 months cannot seem to find problem and it costs me money everytime something is changed.

Tried:

New MAF
New Camshaft position sensor
New throttle body with tps
Reprogram computer
Coils
Plugs

Has anyone else had this issue or have any ideas? I love my Yota but she may have to go if I cannot get this resolved.