P0430 on Hyundai
Catalyst System Efficiency Below Threshold (Bank 2)
P0430 on Hyundai vehicles indicates catalyst system efficiency below threshold (bank 2). Au7o has documented this code across 1 Hyundai model — most commonly on Sonata. 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 Hyundai range from $500 to $2,500, 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 Hyundai by Model
Hyundai Sonata(1 issue)
- P0430 — Bank 2 Catalytic Converter Efficiency Failure (V6)2006-2010
P0430 (Catalyst Efficiency Below Threshold, Bank 2) applies only to the V6 Sonata, which has two catalyst banks. On the 2006-2010 Sonata 3.3L Lambda V6 the bank 2 warm-up catalytic converter degrades so the downstream O2 sensor tracks the upstream sensor too closely, indicating the cat can no longer store/convert oxygen efficiently. Age, high mileage, or upstream causes (an exhaust leak or a lazy/failing O2 sensor) accelerate it.
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What does P0430 mean on Hyundai?▼
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 Hyundai specifically, this code is documented across 1 model.
What causes P0430 on Hyundai vehicles?▼
Common causes on Hyundai: 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 Hyundai?▼
Repair costs on Hyundai range from $500 to $2,500, depending on the specific model and root cause.
Which Hyundai models have P0430 documented?▼
Au7o has documented P0430 on 1 Hyundai model: Sonata.