Notice I didn't suggest he not have a cat, I suggested he have a cat that will work long term. Whatever he has on there now is already throwing codes. Whether he runs a cat long term is up to him and his local emissions rules.

​​​A cheap metal coil cat might be cheaper once, but is more expensive once you've bought and melted 3 of them.

​​​​​​Carbon is one mode of failure. Ignoring a clogged cat is another and the two can happen independently. Both have mitigations but this person already has a suspect or failing cat already, so their carbon situation doesn't feel like a priority?


Coils and planning to do something with the cat is a good plan. If you're going to drive on it at all, at least look inside with your own eyes. If this thread hasn't stated it explicitly enough: a bad cat will slowly kill your engine. Once you know what exactly is going on inside, you can make decisions.