I have a 1986 740 and two days ago it began sounding like a motorcycle. I traced the noise to the exhaust flange that connects the manifold to the tailpipe. I looked underneath the car because I could see the gasket was torn and protruding on one side. When I finally found a gasket and was all set to put it on, I noticed that two of the three 15mm nuts were missing. The only nut remained was the one closest to the engine block. I could not get anything on it that I could apply or obtain the proper leverage to break the nut loose to replace the gasket. I searched the FAQ and it did not cover this area. My question is could I pry the tailpipe loose to use extensions and how difficult is it to reinstall or how do I get to this nut in the rear?