In a few other comments you mentioned you have $100k, but that some portion of that is retirement savings. Don’t lump your retirement savings in with your other savings, even mentally. While they may actually help you secure slightly better loan terms, you should not think of those as available savings. And hopefully they are in a 401k or IRA!

If you have $90k in cc debt you’re clearly living beyond your means.

First step is figuring our where all your money is going. Given you live in Bay Area, a lot probably goes to housing. What else? Student Loans? Car Loans? Dining and drinking? Travel? Expensive hobbies or expensive shopping habits?

You literally need to go through line by line for a few months of spending and figure out what you’re spending all your money on. This wis painful and embarrassing for most people but you will never get a hold on your debt if you don’t know where your money is going.

Once you know where your money is going, you can make a budget so you stop accruing new debt. It’s a simple formula - spend less than you make. But back to my first point, you can’t do that without understanding why you’re spending more than you make.

Once you’re living within your means, are no longer accruing new debt other than interest, and have a surplus in your budget, you can start paying off debt starting with the highest interest cards.

One last thought - if you’re spending some insane amount of your net income on housing, say 50-70% as some bay area folks seem to - and you have an option to live somewhere cheaper without losing income (remote work, in demand industry, etc) living somewhere cheaper for a while certainly wouldn’t hurt the equation.

It sounds like you’re trying to justify buying a car you can’t afford.

Find a dumpy little local muffler shop and they’ll probably weld on a cheapo aftermarket cat for less than $500.

It might also not even be the cat - an exhaust leak or a bad o2 sensor can cause the same error codes. Might just be a couple hundred bucks for a new sensor or some gaskets/welding repairs. My old car was throwing a catalytic converter code and a $3 gasket from autozone fixed it.