Hi-this is my first post. I have an 04' Hyundai Elantra. Starting running really rough and chugging around 40-45 miles an hour. When it comes to a stop it acts like it could die. Changed spark plugs and it ran fine for about 2-2 1/2 weeks. After the next time we changed the spark plug wires and that was about almost 2 months ago. Now it is back and running so terrible. Anybody have this issue or can tell me what to try next.