Cat Converter Shield Broke

Hey all. I was putting on a Greddy SP cat-back. In the process, I chipped off part of the cat converter shield (the part where the bolt is located). I've put the shield back on, but it is only bolted on by 3 bolts, instead of 4. Now when I'm driving, I hear the shield rattling. I was wondering if there's an easy way to fix this (figured I can't use super glue). Or can I just take the cat converter shield off? Do I really need it? Thanks.