So I recently bought 1997 S8 moving up from my 1995 A6 2.8 quattro. After like a week it developed cylinder 5 misfire. I have swapped spark plug,coil,injector from other cylinders also swapped ICM's and itstill remains cylinder 5. Sometimes cilynders next to it also misfires( 1,2,6) but never on 7,8. There is no vacuum leaks from the hoses connected to the front of engine or at the injector. So I am guessing theremust intake manifold gasket leak at the cylinder5. Also I should mention that reding data blocks from running engine misfire is only at idle with warm engine and at idle and slightly open throttle with cold engine. It never misfires at wide open throttle. As far asI can see cylinder 5 and others next to him are getting to much air so I am pretty confident there is a air leak somwhere just want somebody to confirm this or point me to other direction. If Iget confirmation by sunday or if I don't get any repplies I am taking off intake manifold on sunday for further investigation.