Low RPM / Stuttering - Inconsistent

[fixkick]

Hello - 

Got a 96 Tracker 2WD 5 speed. 

I've noticed lately that after I start the car cold, the idle is well above 1000 RPM (as it should be when cold), and then when almost fully warm the idle drops down to ~800 RPM (where it should be?). 
The car drives fine when warm and the idle usually stays around 800 RPM - but sometimes when I come to a full stop and throw the car in neutral, the idle drops  VERY low and the engine stutters (but doesnt die). When this happens, the engine usually brings the idle back up to 800 RPM. 
Its only when I'm accelerating, and then stopping / throwing the car in neutral the RPM dips very low, and stays low for about 10-15 seconds before it starts coming back up. 

This problem isn't very consistent, I sense that when I've been driving the car for a while (at least 15-20 minutes and its very warmed up) the idling problem goes away. 

Any thoughts on what can be causing this? Would it have to do with anything related to the air intake? Maybe some time of air sensor, air leak, or dirty air filter? 

Thanks

are you in USA or Canada and if in USA is it hot or cold there. (Montana and key west,  are not the same) this time of year.  see my simple EGR test below.