Hi,

I am planning to replace the heavily rusted sump on my ST170. This seems like a common issue reading the posts on here.

The bolts on the cat also look badly corroded - will probably need cutting / drilling out.

The question I had - are these bolts "captive" / part of the downpipe / cat, or can I replace these? The cat looks in good shape, so reluctant to replace the whole thing.

Can I get away with just dropping the cat from the downpipe, or do I need to actually remove it?

Thanks in advance for your help.

Steve