P0430
Catalyst System Efficiency Below Threshold Bank 2
Powertrain · Generic (all makes)System: Emissions + Ignition
Safe to drive short term. Book a repair.
Likely causes
- Worn-out bank 2 catalytic converter
- Faulty bank 2 downstream oxygen sensor
- Exhaust leak
- Misfire damage
What to check first
Same diagnosis as P0420, on the bank 2 side: rule out the rear sensor and leaks before replacing the converter.
Typical repair cost
$400 – $2,500
Independent-shop parts and labor for the usual fix. Your price depends on the actual cause and the vehicle.
Next step
General information, not a diagnosis of your vehicle. Repair costs are typical shop ranges, not quotes.