2004 Santa Fe with 130kMy Santa Fe wants to chug when idle or, now, when accelerating and driving. I have already replaced the plugs. Any bright ideas at to what could be causing the chug. It is getting worse over last couple days. Being that it was intermittant prior to now, I changed the plugs when I had time. Now it wants to chug-and-die at idle, hesitates when accelerating, and occasionally hesitates and chugs while driving at higher speeds, too.