Chrysler Repair: 2006 Town & Country Idle issues, throttle position sensor, air control valve

Question
We have a 2006 Chrylser Town & Country with a 3.8L V6 and only 55k miles.  It is having sporadic idling issues where it will either idle too low and try to cut off (and sometimes does) or the opposite where it will idle too high (1500-1800 RPMs).  It does not do it on a daily basis and temperature does not seem to be a factor (either outside or engine).  It also seems to self correct meaning it will do its thing then run fine without having to shut the car off and restart it.  This has been going on for about 9 months and its been to the mechanic a number of times.  So far we have replaced: (1) idle air control valve twice; (2) cleaned the throttle body twice; (3) throttle position sensor; (4) EGR valve; and (5) PCM computer.  We have also had a smoke test performed to check for a vacuum leak and no leak was found.  The engine is also NOT throwing any codes.  This gremlin has gotten the better of us!  Any ideas would be greatly appreciated.

Answer
Hi Austin,
I wrote up a reply but somehow it wasn't sent to you (perhaps my keystroke error).
Basically, you have touched on all the possible causes that I would have suggested. The only item that seems to be related to minivans in the mid-decade model years is that there is a problem with the evaporative emission recovery system which seems to manifest itself most notable after filling up the gas tank. What happens is the engine struggles and dies and then restarts again after waiting a bit, and it appears to be an issue with the device at the tank which separates the liquid from the vapor such that when the engine is prompted to suck vapor from the system instead it gets raw liquid which then causes a too rich mixture and the idle issue starts. Unfortunately Chrysler Corp. does not treat this a recall defect and suggests that the fuel tank be replaced as the solution.
I don't know whether this is involved with your vehicle but you might watch for any coincidence of the occurence with having filled the tank recently. Other than that I would keep trying to do fault code readout immediately after the event using the ignition switch:"on-off-on-off-on and leave on" doing that in 5 seconds or less elapsed time. Then watch the odometer window to see if the mileage reading is replaced by any 4-digit numbers preceded by a P. Let me know if so.
Again sorry for the delay but I assumed you had received this response.
Please 'rate' my answer (see the PS below).
Roland