Probably louder than your local cops would like.
I once had a '96 Dodge truck that suffered that problem. When I pecked on the cat, it sounded like it was full of gravel. The honeycomb guts were breaking up. I ran it for a week or so, without any problems, until I could get scheduled for its replacement. I don't see a need for you to be overly concerned with removing cats before you can get them permanently replaced.