Erratic idle at stoplights, in neutral. Idle bounces constantly and gets worse when hot outside.

What is your question?

Can't find any vac leaks. Replaced lots of parts: IAC, TPS, Coolant Temp sensor, intake hose, air intake temp sensor. Idle still bounces while sitting at stoplight in neutral; gets worse and worse as outside temps increase (summertime). What else to try?