Also, my '95 Contour also had the rattle you described (at 2000-2500 rpm), even after replacing the factory recalled cat on it. And it turned out to be coming from a heat shield that is mounted above the cat, on the floorboard (that keeps the cat's heat from getting through to the doghouse/ firewall/ floorpan area. I just made a simple aux. support bracket to hold it better, and now the rattle is gone.
'95 CONTOUR SE
-Enkei 16s
-Porsche944 Exhaust tip
-
Audi xenon projector headlights
-Peterbilt 30" air horns
-mp3 Aiwa headunit (150 songs on one disc)
-dual 10s
-soon to have LED tailights (real kind, not just gay bulbs)
-That's it for now