P0430 on MINI
Catalyst System Efficiency Below Threshold (Bank 2)
P0430 on MINI vehicles indicates catalyst system efficiency below threshold (bank 2). Au7o has documented this code across 1 MINI model — most commonly on GP. 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 MINI range from $800 to $3,000, 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 MINI by Model
MINI GP(1 issue)
- Cracked Exhaust Manifold (Turbo Models)2013-2023
The cast iron exhaust manifold (integrated with the turbo housing on the N18/B48) is prone to cracking from thermal stress. The GP engines produce higher exhaust gas temperatures than standard MINI models due to their aggressive tuning. Cracks develop at the cylinder-to-manifold flanges, causing exhaust leaks, a ticking noise, and potential turbo bearing damage from escaping exhaust gases. Track use and hard driving significantly accelerate cracking.
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View P0430 across all makes →Frequently Asked Questions
What does P0430 mean on MINI?▼
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 MINI specifically, this code is documented across 1 model.
What causes P0430 on MINI vehicles?▼
Common causes on MINI: 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 MINI?▼
Repair costs on MINI range from $800 to $3,000, depending on the specific model and root cause.
Which MINI models have P0430 documented?▼
Au7o has documented P0430 on 1 MINI model: GP.