P0430 on a Nissan: Causes, Fixes & Repair Cost

🟠 Moderate severity · drivable

Drivable in the short term, but the bank 2 converter problem should be checked soon.

What P0430 means on a Nissan

On a Nissan, P0430 means the rear oxygen sensor on bank 2 sees the catalytic converter cleaning exhaust below expected levels. It's the bank 2 version of P0420 and mainly appears on V6 Nissans.

Is P0430 common on Nissans?

Nissan V6 models like the Maxima, Pathfinder, and Frontier are where P0430 usually shows up, typically at higher mileage. Worn converters and downstream oxygen sensors are the common culprits, with exhaust leaks as a less common trigger.

Commonly reported on: Maxima, Pathfinder, Frontier, Murano.

Symptoms

Check engine light is on
Reduced fuel economy
Possible rotten-egg smell from the exhaust
Often no noticeable driving symptoms early on

Common causes

most common: Worn or failing catalytic converter on bank 2
common: Faulty downstream oxygen sensor on bank 2
common: Exhaust leak before or near the downstream sensor
less common: Unfixed misfire or rich fuel mixture that damaged the converter

How to fix it

Fix	DIY?	Typical cost
Inspect for exhaust leaks and repair them before replacing anything	Yes	$50–200
Test the downstream oxygen sensor and replace it if faulty	Yes	$60–200
Replace the bank 2 catalytic converter	Mechanic	$600–2500