P0430 on Audi
Catalyst System Efficiency Below Threshold (Bank 2)
P0430 on Audi vehicles indicates catalyst system efficiency below threshold (bank 2). Au7o has documented this code across 1 Audi model — most commonly on R8. 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 Audi range from $3,000 to $10,000, 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 Audi by Model
Audi R8(1 issue)
- Catalytic Converter Failure Requiring Engine-Out Replacement2008-2023
The R8 runs four catalytic converters, with two primary cats integrated into the exhaust manifolds. Internal cat breakdown is a recurring failure that throws catalyst-efficiency codes and fails emissions testing. Because the primary cats are part of the manifold assembly deep in the engine bay, replacing them typically requires pulling the engine, making this one of the most expensive non-engine repairs on the car. Some owners also report cracked manifolds on certain 2010-2012 V10s.
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What does P0430 mean on Audi?▼
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 Audi specifically, this code is documented across 1 model.
What causes P0430 on Audi vehicles?▼
Common causes on Audi: 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 Audi?▼
Repair costs on Audi range from $3,000 to $10,000, depending on the specific model and root cause.
Which Audi models have P0430 documented?▼
Au7o has documented P0430 on 1 Audi model: R8.