Just learned the rattling noise I've been hearing is something lose or broken inside the catalytic converter. Is this normal?
Catalytic Converter on 1998 Isuzu Oasis
Its not a common problem, but it does happen. The substrate catalyst material can break down or break apart into chunks and (exactly as you stated) rattle around inside the casing. The only solution is to replace the converter.
Thank you for your response. I've been pricing them & boy, are they ever expensive! But if it'll help my van smog next month, then I guess it's worth it. Thanks again!