I wrote this question. Found a small rag jammed into the throttle body, obstructing the butterfly valve. WOW. Glad it didn't get sucked into a cylinder. And no, this was not my fault. I bought the car used and this is exactly how I found it when I yanked off the TB. Engine idles at proper speed now. A little rough at times, but I bet changing the 02 sensors will cure that.
It's still under warranty, take it to the dodge dealer.
vacuum leak
its your engine control module>>>JAC
may have plug wire crossed
Acceleration Cable broken broken, you dump!
Adjust the idle screw.
zyou tps might be bad
On my Chevy truck it idles high when its low on antifreeze but if its not that more than likely its usually a vacuum line loose or cracked. good luck.
If the engine idles and revs up okay in neutral, it is likely the torque converter clutch lock up solenoid.
why does my 4.75 BRIGGS & STRATTON lawnmower engine idles high and low when cutting my grass
Your Idle Air Control valve may be sticking. Or the engine oil is to cold, thickens there is more power needed to crank the engine.
Need a little more info. What Model and year of the vehicle?