'98 LX 'tour 2.5 duratec MTX, sometimes at startup, other times when sitting at a light, cant figure it out, cleaned MAS, replaced PCV, changed out air filter, i dont know what else it could be and i couldnt find a thing out by searching, i know im a n00b, but i did try the search first, just didnt turn up any results... help is needed... thanx in advance