my 95 mystique (zetec, mtx, 95,500 miles) has been running roughly at idle and when cold, so i have been trying to take some steps to change this. i changed the fuel filter, which didn't help the problem. i tried to change the plugs today and i could not get them to turn at all. has anyone else had this problem? the best suggestion i have heard so far is spray some penetrating oil around each plug, give it a week, and pray that it works, or else you'll be trying to rethread an aluminum head, which does not sound like a whole lot of fun. i think the original plugs are still in there.
