P0430 on Acura
Catalyst System Efficiency Below Threshold (Bank 2)
P0430 on Acura vehicles indicates catalyst system efficiency below threshold (bank 2). Au7o has documented this code across 1 Acura model — most commonly on TSX. 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 Acura range from $300 to $1,800, 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 Acura by Model
Acura TSX(1 issue)
- Catalytic Converter Efficiency Loss Setting P04202004-2014
TSX owners across both generations report recurring P0420 (Catalyst System Efficiency Below Threshold, Bank 1) as the front catalytic converter loses efficiency. On the first-generation K24A2 cars this is frequently a downstream consequence of the oil-consumption problem - oil ash coats and poisons the catalyst substrate long before its normal service life. On the V6 cars the J-series family is separately documented for the catalyst substrate breaking apart, producing a loose rattle inside the converter shell. Beyond the check engine light, the practical consequence is a failed emissions inspection. Catalytic converters carry the federal 8-year/80,000-mile emissions warranty, which most of these cars are now well past.
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What does P0430 mean on Acura?▼
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 Acura specifically, this code is documented across 1 model.
What causes P0430 on Acura vehicles?▼
Common causes on Acura: 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 Acura?▼
Repair costs on Acura range from $300 to $1,800, depending on the specific model and root cause.
Which Acura models have P0430 documented?▼
Au7o has documented P0430 on 1 Acura model: TSX.