I searched under plenum gunk and didn't find what I was looking for. About two days ago I finished replacing the PCV's (PITA) and while I had the balance tube off I saw that inside the plenum there was a $h.t load of black gunk, put my finger on it and had a build up on it. What is that caused by and how can I clean it out besides using Sea Foam, I've heard good things about it and bad I'm sure the TT will run much better after it is cleaned out. Would that cause or have something little to do with exhaust smoke?
