The catalytic converter reduces harmful exhaust emissions by chemically converting CO, HC, and NOx into CO2, water, and N2.
Hot exhaust passes through a ceramic honeycomb coated with platinum, palladium, and rhodium — the precious metals catalyze the reactions.
Product picks are curated by our team based on what shops actually use. Links go to Amazon; as an Amazon Associate we may earn a small commission — it never changes the price you pay.
Replacement runs $900–$2800 including parts and 1-3 hours labor. Exact cost depends on vehicle, parts tier (OEM vs aftermarket), and local labor rate.
Expected lifespan is 100,000-150,000 miles. Driving conditions, climate, and maintenance affect real-world life.
Check-engine light P0420 / P0430; Rotten-egg sulfur smell; Loss of power; Rattle from under the car; Failed emissions test.
Most modern catalytic converters are sealed units that get replaced rather than rebuilt. A shop will diagnose, confirm with a load or output test, then swap the unit and verify operation.