I agree - the exhaust bolts on my '98 Cavalier, holding the cat into the exhaust system, had all but disintegrated (they looked like little pins) - and everything still held together.Something smells. I can't imagine the bolt shearing off without mechanical stress. What's the story on the other bolt? I'm wondering if the one we see was sheared at the factory and it's been on one bolt all this time. I sure don't see any fresh damage on it - like a clean face like I'd expect to see.
The OP is a diesel......that is the flange at the catalyst they use......the diesel has no muffler.There's one post here with a welded system ... and to my knowledge/past experience, I don't recall there being flanges near the muffler on two vehicles that I've replaced the exhaust on with aftermarket. Are you the original owner? Is it a 1.4 or 1.8? If you're not the original owner, I wonder if some exhaust work was done for whatever reason ... but then again, with parts of the cars being made outside the U.S. I can imaging the quality control isn't the greatest, nor is the material being used. Best of luck with that one! If you have a good dealership and you're the original owner, they should help you out. (He!! ... even if you're NOT the original owner, they should help you out)
...my dealer told me about a year ago that my exhaust separated somewhere under the car and caused a code to set. The dealer had no idea what had caused the separation - but suspected that it was ice damage. They replaced the bolt at no charge and I haven't thought about it since.