P0430: Catalytic converter efficiency below threshold (bank 2)

What does it mean?

System

Powertrain (engine and transmission)

Subsystem

Emissions (EGR, catalyst, particulate filter, vapours)

Type of code

Generic code: means the same on every make.

How urgent?

No immediate danger, but have it checked at the next opportunity: fuel use and emissions can rise, and the car can fail its inspection.

Possible causes

• Catalytic converter worn out
• Downstream oxygen sensor reading wrong
• Exhaust leak before or after the catalyst
• Upstream cause: misfires or a rich mixture damaging the catalyst

Tip: don’t just clear the code. Clearing a code doesn’t fix the cause. It often comes back, and the stored data that helps us find the cause is then gone.