Noisy cats

I have a question.
2 days ago the cat on the passenger side started makin a noise, it sounds like simething is broken inside the cat
It's gettin louder.
According to the previous owner he changed the
18 months ago
But my question is. Are they gone?
Cuz it has 16k miles on the "new" cats
Thanks 4 da help

yeah you prolly need a new one. get you some high flow cats from ebay they are around $40 bucks

I was thinking bout to do that
But since I'm in Cali they ant wanna send em to me
Cuz they r illegal.