Patrick,
hey I've got a '95 Mercury Mystique V6. I had a similar problem. My dfpt hose kept popping off. Eventually, I started to experience sever performance problems. It got to the point where the back pressure was limiting my speed to less than 50mph at full throttle.
Problem: Main cat had collapsed or become blocked.
Solution: Replaced main cat (and rest of exhaust with SVT while I was at it) and installed worm clamps on dfpt hoses at manifold side.
Good luck.
I found cats on the net for 170.00 or so. I bought mine from another CEG'r
