I am having difficulties with Ford and my car. I have an erratic idle that from time to time will stall, including when I throw in the clutch while driving. First thing Ford tried to blame was my K&N air filter. Knowing this was incorrect, I tossed in my original filter to prove a point and sure enough it was still doing it. I now have Ford telling me they can't find anything wrong since the diagnostic computer says everything is fine.

...I guess nobody knows how to fix cars anymore if the computer can't do the diagnostics.
Anyone had this idle problem? Sounds like an idle control valve or something related. Thoughts? I'm wondering how long I'll be driving the TownCar at this point. Not a bad loaner. I just don't want my car back till it's fixed.
Thanks