P0430 fault code: what it means

P0430: Bank 2 catalytic converter is not cleaning the exhaust well enough (V engines).

Engine and gearbox (powertrain) · Costly if missed

Usual causes, most likely first

worn bank 2 catalytic converter
aged bank 2 rear O2 sensor
exhaust leak before the rear sensor
misfire on bank 2

P0430 by make

BMW

Catalytic converter efficiency low, bank 2 (cylinders 4-6 on a straight six).

Usual causes: worn catalytic converter; rear oxygen sensor; exhaust leak before the sensor

Honda

Catalytic converter efficiency low (bank 2). On Honda J35 V6 bank 2 is the front converter; often seen with P0420 after VCM oil burning or misfires.

Usual causes: worn or oil-contaminated front catalytic converter; misfires or leaking injectors overheating the converter; oxygen sensor fault

Jeep

Catalytic converter efficiency below threshold, bank 2.

Usual causes: worn catalytic converter; rear O2 sensor bank 2; exhaust leak

Mercedes-Benz

Catalytic converter efficiency below threshold, bank 2 (V6/V8).

Usual causes: worn or split catalytic converter; faulty rear O2 sensor; exhaust leak before the sensor

Nissan

Catalytic converter efficiency low on bank 2 (V6/V8). Often seen with P0420.

Usual causes: worn bank 2 catalytic converter; bank 2 rear oxygen sensor fault; exhaust leak before the sensor

What the repair usually costs

Air-fuel ratio / front O2 sensor replace (upstream)NZ$270–NZ$750 · A$260–A$730
O2 sensor replace (downstream / after cat)NZ$180–NZ$480 · A$180–A$460
Catalytic converter replace, aftermarket direct-fitNZ$570–NZ$1,570 · A$540–A$1,490
Catalytic converter replace, genuineNZ$1,640–NZ$5,160 · A$1,470–A$4,590

Not sure what P0430 means on your car? Ask Credov.

Before you clear it

Write the code down or photograph the scanner first. A code that comes straight back after clearing points to a fault that is still there. A car whose codes were cleared just before you arrived may be hiding one: the scanner's readiness monitors show "not ready" for a while after codes are cleared.

Researched by Credov from manufacturer and workshop sources. A fault code points to where a fault may be; a workshop confirms it with a diagnosis. Browse all fault codes.