UPDATE: Finally got tired of hearing the exhaust loudly "wheezing" and the really embarrassing look when going down the road. Three days ago I jacked it up to see where the problem lies. When I cut the old Cat out I noticed the exhaust pipe connection was not round but oval shaped. The exhaust pipe clamps, at the union, were only tightened with the ratchet and had not really formed around the oval shape of the exhaust pipe. I repositioned the clamps and used a breaker bar with an extension pipe and really cranked down on the nuts. It has been quiet and no exhaust leaks.