Removing cats performance gain

[mmikeman]

Noticing my cats seem to rattling / making a hising noise was interested in just taking them out completly I recall doing this on a Lincoln towncar ..the process wasn't fun and resulted in exhaust leaks near the manifold in the end since the towncar had cats all the way up jammed into the motor, now I'm wondering if removing all the cats is going to get me any gain with a 97 Lincoln mark and if its going to be just as hard to remove as the towncar? I'm thinking of removing the cats and putting after market mufflers on for sound/power gain

 

[Sapperfire]

Driver cat is part of the manifold

 

[chris2523]

do cobra manifolds and dual exhaust.