[Gasoline Fumes]

It's hard to say how well the catalytic converter is working without an emissions test. I drove my car without a cat for a while and it stunk like an old lawnmower. A bad O2 sensor should eventually give you a check engine light.

Don't pay $120 for that rusty muffler! I'd sell you mine for a lot less! It's heavy, but it's quiet and will fit.