Looking for some help here. While coming to a stop, my engine revs very high. This happens mostly at traffic lights. I can lower the idle and stop the racing, by letting out on the clutch, while in gear. This drops the idle and it stays normal until the next stop. As far as I can tell, the engine has no Mods done and the exhaust, etc is stock. I have an "05" S model, that was purchased used and has 4100 miles on it. This also seems to happen mostly after being run for a while.