Catalytic Converter Replacement Cost

Average Cost Range

• Aftermarket converter: $800–$1,400 parts + labor
• OEM converter: $1,200–$2,500 parts + labor
• Labor: 1–2 hours typical ($100–$200)
• California-compliant (CARB) converters cost more and are required in CA, NY, and several other states

What Is P0420?

Code P0420 (Catalyst System Efficiency Below Threshold) is the most common reason for catalytic converter diagnosis. It means the downstream oxygen sensor is detecting that the converter isn't cleaning exhaust gases efficiently enough. P0420 almost always means a failing converter — but first rule out a bad O2 sensor or exhaust leak, which are cheaper fixes.

Why Are Catalytic Converters So Expensive?

Catalytic converters contain platinum, palladium, and rhodium — precious metals that process exhaust gases. These metals are expensive, and their prices fluctuate with commodity markets. That's also why catalytic converter theft has surged — thieves can sell stolen converters to scrap dealers for $50–$600 each.

OEM vs. Aftermarket Converter

• Aftermarket converters are legal in most states and cost 30–50% less
• California, New York, and several others require CARB-compliant converters (more expensive)
• OEM converters typically last longer and clear codes more reliably
• Some aftermarket converters cause P0420 to return — always use a reputable brand (Magnaflow, Walker)

Can I Drive with a Bad Catalytic Converter?

Usually yes — a failing converter won't cause the car to break down immediately. But it will fail emissions testing, and ignoring it long-term can cause the converter to collapse internally and restrict exhaust flow, which can cause overheating or engine damage. Fix it before your next inspection.