P0430 on a Lexus: 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 Lexus

On a Lexus, P0430 tells you the bank 2 catalytic converter isn't cleaning exhaust efficiently, based on the rear oxygen sensor reading. It's the same family of problem as P0420, which owners of V6 and V8 Lexus models see more often.

Is P0430 common on Lexuss?

Lexus V6 and V8 models like the RX, GX, and LX show P0430 mainly at higher mileage, when converters or oxygen sensors start to wear. Because Lexus shares its platforms with Toyota, repair patterns and parts are similar.

Commonly reported on: RX, GX, LX, GS.

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	$900–3000