the ICSV is located under the throttle body on the O/S side of the inlet tracks, there should be a 2 pin plug going to it (two 8mm bolts hold the unit on) i would try cleaning it before replacing it -they are around 80 quid from motor factors so its worth a try, it worked with mine- just leave the end of it in some petrol or diesel for an hour a few toots of carb cleaner/brake cleaner should do it, after replacing the unit allow the car to idle for 5 mins to allow the ECU to memorise the new idle values.