[HALP] Clogged Cat?

File: 1e510b69-ef6e-46e8-a576-31d43ffc9e08..jpg (132KB, 939x527px) Image search: [Google]

132KB, 939x527px

TLDR: how to tell if clogged cat without ripping off cat?

I have an OBD2 97 mk3 Jetta I'm fixing for someone. It's been throwing codes for the cat for a while now, but also some other things including the cam shaft position sensor (however this code comes and goes). The car has been losing power over the months and eventually started stalling in parking lots if it wasn't given any power. It's an automatic if it makes any difference. The car now stalls right after starting, like it runs for all of a second and then dies instantly. Is there an easy way for me to make sure it's the cat and that it's completely clogged? I can't seem to get the bolts off to just rip it off, so I might have to just buy a thicc drill bit and punch a bunch of holes in it before I can get it to a muffler shop. However, I want to make sure it's the cat before I destroy it. Any tips?

pic related