general problems of the 2010 Dodge Nitro

Outside temp was approx 30-35 f, engine was running aprox 10 mins,while accelerating from 30mph to 50 mph on the highway, the gas pedal stayed to the floor after I took my foot off, causing vehicle to continue accelerating to a higher mph. I put transmission selector into neutral, engine raced to a higher rpm, used brakes to slow vehicle down and exited highway. When I stopped the vehicle, I shut off ignition and heard the gas pedal pop back into position. After approx 2 mins, I restarted engine and everything seemed normal. Has not recurred as of yet. Called major Chrysler Jeep Dodge service department to inquire if they've had this type of incident, they said no. They checked if vehicle was still under warranty, no it was not. They offered diagnostic check but I scanned the aldl for computer codes, none.