P0430 on Infiniti
Catalyst System Efficiency Below Threshold (Bank 2)
P0430 on Infiniti vehicles indicates catalyst system efficiency below threshold (bank 2). Au7o has documented this code across 1 Infiniti model — most commonly on FX35. This code means the catalytic converter on Bank 2 (the side of the engine that does not contain cylinder #1) is not reducing emissions as effectively as it should. The computer compares the readings of the oxygen sensors before and after the converter; if the downstream sensor's signal starts mirroring the upstream one, it indicates the converter is no longer storing and processing oxygen properly. This usually points to a worn-out or damaged catalytic converter, but it can also be caused by faulty sensors or upstream engine problems that have poisoned the converter. The car will generally still run, but it will fail an emissions test. Typical repair costs on Infiniti range from $600 to $3,500, depending on the specific model and root cause.
Common Causes of P0430
- •Worn-out or failed catalytic converter (Bank 2)
- •Faulty downstream (post-cat) oxygen sensor
- •Faulty upstream oxygen sensor giving bad data
- •Exhaust leak near the converter or sensors
- •Engine misfire or oil/coolant burning that damaged the catalyst
- •Running too rich or too lean over time
- •Aftermarket or non-compliant catalytic converter
P0430 on Infiniti by Model
Infiniti FX35(1 issue)
- Catalytic Converter Efficiency Failure (P0420 / P0430)2003-2008
First-generation FX35s commonly set P0420 and/or P0430 (catalyst efficiency below threshold, bank 1/bank 2) as the two close-coupled converters degrade, often between 80,000 and 130,000 miles. Contributing causes on this engine are oil consumption coating the catalyst and rich running from failed coils/plugs or sensor faults. Dealers quote about $1,500 per converter plus labor, with the OEM manifold-integrated cats being the expensive part. Aftermarket high-flow cats compatible with the G35/350Z are a common lower-cost route, and replacing downstream O2 sensors alone often does not clear the code.
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What does P0430 mean on Infiniti?▼
P0430 stands for "Catalyst System Efficiency Below Threshold (Bank 2)." This code means the catalytic converter on Bank 2 (the side of the engine that does not contain cylinder #1) is not reducing emissions as effectively as it should. The computer compares the readings of the oxygen sensors before and after the converter; if the downstream sensor's signal starts mirroring the upstream one, it indicates the converter is no longer storing and processing oxygen properly. This usually points to a worn-out or damaged catalytic converter, but it can also be caused by faulty sensors or upstream engine problems that have poisoned the converter. The car will generally still run, but it will fail an emissions test. On Infiniti specifically, this code is documented across 1 model.
What causes P0430 on Infiniti vehicles?▼
Common causes on Infiniti: Worn-out or failed catalytic converter (Bank 2), Faulty downstream (post-cat) oxygen sensor, Faulty upstream oxygen sensor giving bad data, Exhaust leak near the converter or sensors, Engine misfire or oil/coolant burning that damaged the catalyst. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0430 on a Infiniti?▼
Repair costs on Infiniti range from $600 to $3,500, depending on the specific model and root cause.
Which Infiniti models have P0430 documented?▼
Au7o has documented P0430 on 1 Infiniti model: FX35.