I have a 2006 3/4 ton dodge cummins with 140k on it. I have never had a single problem with this truck until now. yesterday i drove about 30 miles on the hwy and then when i came to a stop at my destination i pressed the brakes and let off the accelerator. The engine remained at a higher idle than usual and when i let off the brake it started peeling out in the gravel. when i put it in neutral the truck idles down to regular rpm. put it in reverse and the idle rises and the same peeling out happens when letting off the brake. put it in park and the idling stops. Any ideas on whats wrong?

 

TPS semsor