P0430: Catalyst System Efficiency Below Threshold (Bank 2)
29 vehicles · 15 makes · $100-$6,000 repair
Most Reported On
P0430 is an OBD-II diagnostic trouble code meaning “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. This code is most commonly reported on 2007-2019 Toyota Tundra (1794 Edition, Base, Limited, Platinum, SR, SR5, TRD Pro), 2004-2012 Mazda RX-8, and 2006-2019 Volkswagen Beetle, plus 26 other vehicles, with repair costs ranging from $100 to $6,000.
Common Causes
Typical Repair Cost
Based on 30 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
To diagnose P0430, you'll need an OBD-II scanner. Here are our recommendations at every price point.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).
- Read & clear engine codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.
- Enhanced diagnostics (ABS, SRS, transmission)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X OBD-II Scanner
by LAUNCH
A professional-grade handheld scanner that reads all four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.
- Engine, transmission, ABS, SRS diagnostics
- Live data stream & graphing
- AutoVIN for vehicle identification
- Free lifetime updates via Wi-Fi
Autel MaxiCOM MK808S Diagnostic Tool
by Autel
Shop-level diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
As an Amazon Associate, we earn from qualifying purchases. Prices are approximate and may vary.
Vehicles Affected (29)
Exhaust Manifold Bolt Failure and Leak
Catalytic Converter Theft Vulnerability
Exhaust Manifold Cracking (Both Banks)
Premature Catalytic Converter Failure
Exhaust Manifold Cracking
Catalytic Converter Premature Failure (Bank 1)
Premature Catalytic Converter Failure
Exhaust Manifold Cracking and Bolt Failure
Cracked Exhaust Manifolds on 4.7L V8 Causing Ticking Noise and Exhaust Leaks
Pre-Catalytic Converter Disintegration (Spyder)
Exhaust Manifold Cracking (4.7L 2UZ-FE V8)
Pre-Catalytic Converter Disintegration
FAQ
What does P0430 mean?
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.
What are the most common causes of P0430?
The most common causes of P0430 are: 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. The specific cause varies by vehicle.
How much does it cost to fix P0430?
Repair costs for P0430 range from $100 to $6,000, depending on the vehicle and root cause.
Which vehicles are affected by P0430?
Au7o has documented P0430 across 29 vehicle models from 15 manufacturers: Chevrolet, Chrysler, Dodge, Ford, Honda, Jeep, Kia, MINI, Mazda, Nissan, Opel, Porsche, RAM, Toyota, Volkswagen.
Sources (12)
- Forum2015 Kia Soul Engine Issues Failed cat converter - Kia Soul Forums
- ForumBlown Engine Due to Catalytic Convertor - Kia Soul Forums
- ForumThe Dreaded Soul Catalytic Converter Issue - Kia Soul Forums
- ForumFAILED CATALYTIC CONVERTER NOW ENGINE COMBUSTION FAILURE - Kia Soul Forums
- newsNV200 Prime Target for Catalytic Converter Theft
- Forum1ZZ Pre-Cat Engine Failures - MR2 SpyderChat
- ForumCatalytic Converter Engine Failures Post Yours - MR2 SpyderChat
- ForumPre-cat failure - not overseas myth - MR2 Owners Club NZ
- ForumPre Cat Cat Failure - MR2 SpyderChat
- NHTSANHTSA Vehicle Complaints - 2002 Honda Passport (engine / exhaust-related complaints)
- ForumJeepForum threads on 4.7 exhaust manifold bolt breakage and ticking
- RecallNissan Recall 20V123000 - Exhaust Manifold Cracking on Certain Nissan Vehicles
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.