When I start my Durango in the morning it seems to surge/race. The rpm can sometimes reach 2000 rpm. Now when I am sitting at a light, it surges/races from the 500 rpm to 1000 or so rpm with my foot on the brake. No check engine light comes on. Could it be the tps or another switch/sensor? I have about 85000 miles on it.

 

I would look at the TPS,
FF

 

Give the throttle body a real good cleaning inside as well. Like Fascistfaction says though the TPS could be the problem. Good news they are under$40.00 and easy to change. Any funny tranni shifting? they sometiems go hand in hand. My 04 4.7 was shiffting od and it was the TPS. Also do you have a CAI or exhaust?

 

Yes it is shifting funny.

 

I found that it would be the IAC Idle Air Control.

Remove from the throttle body and clean real good with Throttle body cleaner.
Also clean inside the throttle body and wipe with a good lint free cloth. You will get a rag full of black carbon. The IAC is sticking from the carbon build up.

My Dodge quad 1500 with the 4.7 was doing that when I first started in the mornings and would surge. When warm ok. Might have to do maybe 2-3 times a year with a good cleaning.

Disconnect you ground battery cable
remove the aircleaner and on the 4.7 it's the module on the top with an electrical connector. Bottom is the tps

You will need a torx driver to remove the torx screws same for the TPS