Catalytic converter = Exhaust cleaner.*1. Engine burns fuel and makes dirty poisonous gases — CO, HC, NOx.
2. Those gases pass through the converter.
3. Inside, Platinum / Palladium / Rhodium triggers a chemical reaction that turns them into clean gases — CO2, Water, Nitrogen.
Without it:* your car will be loud, smell bad, burn more fuel, show check engine, and pollute.
That's it. One sentence: *It turns harmful exhaust into harmless exhaust