I just got a 2013 Dodge Dart with 98 thousand miles . Within the first week of owning it, I drove it just around my block and when I would press on the throttle then let go it would stay at the same rpm from when I was pressing it for a few seconds? After it warmed up it would stop. Any ideas what it might be the cause. Also on two other occasions when I would press the gas the speedometer would slicker along with the radio and cabin lights. My radio also won’t stay connected to my phone.