this isnt really the normal cat post. i just got a 1997 f150 4.6L and the previous owner had cut the pipe coming from the manifold to the cat and replaced it with flex pipe. flex pipe is the most stupid exhaust fix ever because it doesent seal so i have a leak under the drivers side and it is really loud. so im wondering if i could maybe get an elbow to put there and weld it in (i would also like to put a new cat back exhaust on) or if there is a way to remove the cat and put a new exhaust on

 

Flex is not only stupid but illegal in any part of the exhaust system.
A muffler shop may be able to piece in a section.
Me, I would replace that whole side for the $300 cost +/- and have it correct and have new cats on that side.
If this was done both sides, replace everything.
There are some dumb things people do trying to save a buck.
If you knew this was the case, should have offered less on the price to cover repairs.
Good luck.

 

Won't that throw it off with only one cat