Chrysler Repair: Rough running after engine warms up, but no codes, chrysler 300 touring, 2006 chrysler 300

Question
I have a 2006 Chrysler 300 Touring with the High Output V6.  When the ambient external temperature is above 65 degrees my car, after reaching operating temperature will sputter when stopped, while in gear, at things like traffic lights or stop and go traffic.  It would run smooth then sputter and feel as though it will stall.  In cool weather I do not have this problem.  The last warm day in the north east it began to stall.  The check engine light does not come on.  I have had it to the dealer, there were no error codes and the day I brought it in it was cool, obviously they could not reproduce the problem, and sent me on my way.  Do you have any clues on what this might be or where to start the diagnosis process?

Answer
Hi Anthony,
The year of your car is a bit too new for my ability to have a service manual for it.
On general principles the sensors that affect fuel mixture are the ones that are most likely involved in your problem. I would suggest that the temperature sensor for the incoming air, located in the intake manifold, may be inaccurate but no so greatly as to set a fault code. You can look for the device to be screwed into the external surface of the intake manifold.  It has two wires (black/light blue and black/red, at least those are the codes used by Chrysler in earlier model years) and you could check to see if the resistance measured across the terminals of that sensor after removing its plug (lift tab gently to release) reads a significantly different ohm value on a cold day as compared to a warm day after the engine has reached operating temperature. If not, then that may be the cause.
Other than that, you may have to wait for the check engine light to come on when the engine is running which would be a sign that a fault has been detected and stored as a code in the memory of the powertrain controller. That would be the most helpful diagnostic information.
I hope this is helpful.
Roland