You sure it's exhaust not a leaking valve cover? Also, although it could be an issue with manifold leaking, I wonder if maybe it's another joint in the exhaust system.
You just had service II done. Did they do anything around the exhaust? O2 sensors maybe...maybe your front exhaust bracket is loose and put pressure on a fitting?
Upcoming NYC dates: Jan 8 and 27. See Facebook for other shows and PM me if you can make one...love to see you there!
Mangofy your E46!