to be done? From what you are saying, may be it is a computer thing? I haven't received a check engine light yet, so I guess it isn't idling "that bad," but its definitely off and needs to be addressed. I would suggest cleaning the IAC valve first. I don't know where it is on the zetec but it will be right around the throttle body. Hopefully it's easy to get to. edit: couldn't find a how-to with working pictures but that certainly looks like a pain to get to. Not the worst though I'm sure. You don't have to remove the manifold, but You'll be getting at it from the bottom. It's on the plastic manifold on the back of the engine. Here's a good picture I found of it at least. Is the idle bouncing? I could be a bad bearing or ac clutch in the compressor. Turn the car on and turn the ac on. Pop the hood and look at the serp belt. The pulley at the bottom is the ac pulley. If its a bouncing idle you should see the pulley freeze momentarily and then kick back on I have this in my car. Good luck, I suggest exhausting every possibility for diag before throwing the parts dart and buying tons of stuff that you don't need to replace Thanks for all the help guys. I am going to give the AC bearing a check. May be it will be something fairly simple. Im new