About a week ago my 2013 Elantra started idling hard when stopped, almost shaking the whole car. About 3 days ago, it started happening while driving as well. Today it was shaking hard at the stop light and when I started to accelerate it never stopped, almost got worse and then the engine light went on. I decided to rearrange my day and run by the parts house to see if they could read the code but the light went off before I could make it there. So I’m at square one still.