so i have been searching all day for some one that had the same issue as me, my car misfires at idle and when i get on it, it kinda bog for a sec and goes but it backfires also, do u think i just need a spark plug change? here is what it sounds like at idle,

http://www.youtube.com/watch?v=e0TgrEpD19I

this isnt my car but it sounds just like that. sometimes it gives one big loud bang.