I havent done it yet, most like next spring when I should be aropund 60K, but is it a must to remove the upper plenum to do it? I was looking around today cleaning the engine bay up. It looks like if you use swivels and a long extension it might be doable without removing anything. I can get an extension and swivel and short socket on the coil bolt(didnt remove them though), and it seems like a plug socket,swivel and extension should go down the plug tubes once their out. I think the worst one would be the #3 plug(i think) which is almost in the middle of the plenum, but it looks like it should be too bad. Anyone try this route instead of removing the whole upper part of the engine?