This vehicle was purchased from a private party 12-30-2019. It has a total of 28,000 miles. I have driven it approximately 50 miles since purchase. It starts, drives, and runs perfectly. However, after driving for approximately 20-30 minutes at highway speed and then decelerating to a stop at a traffic light, the car starts to idle normally, then just dies. It will restart immediately, however, if I continue to allow it to idle in gear while stopped, it will die. It does not run rough at idle, it just dies. It will restart and run perfectly once you apply throttle. If I put the car in neutral at idle, it remains running.

I would appreciate any input on a possible fix.