P0430
Medium SeverityCatalyst System Efficiency Below Threshold (Bank 2)
Emissions System
What Does P0430 Mean?
Same as P0420 but on bank 2. If both P0420 and P0430 are present, the issue may be systemic (engine running rich, etc.).
Common Fix
Replace cat bank 2 or fix root cause
Estimated Cost (DIY)
$100 - $1,500
Common Causes
How to Diagnose P0430
- 1Same approach as P0420 but on bank 2
- 2If P0420 also present, check for engine-wide rich condition first
OEM Diagnostic Flowchart
Scroll to load technician if/then branches.
Read live data and freeze frame for P0430 to pinpoint the cause before buying parts.
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Related Resources
Repair guides, symptom pages, and wiring diagrams related to P0430.
OEM Manual Evidence
Browse →A L L Diagnostic Trouble Codes ( DTC ) — 2013 GMC Truck Yukon XL Denali AWD V8-6.2L Service Manual | Operation CHARM Operation CHARM : Car...
A L L Diagnostic Trouble Codes ( DTC ) — 2013 GMC Truck Yukon XL Denali 2WD V8-6.2L Service Manual | Operation CHARM Operation CHARM : Car...
A L L Diagnostic Trouble Codes ( DTC ) — 2013 GMC Truck Yukon XL 4WD V8-6.0L Service Manual | Operation CHARM Operation CHARM : Car repair...
A L L Diagnostic Trouble Codes ( DTC ) — 2013 GMC Truck Yukon XL 4WD V8-5.3L Service Manual | Operation CHARM Operation CHARM : Car repair...
Related Symptoms
Browse →Exact Vehicle Hubs
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Open the exact vehicle hub for a repair workflow commonly associated with P0430.
Open the exact vehicle hub for a repair workflow commonly associated with P0430.
Open the exact vehicle hub for a repair workflow commonly associated with P0430.
Open the exact vehicle hub for a repair workflow commonly associated with P0430.
Open the exact vehicle hub for a repair workflow commonly associated with P0430.
Exact Repair Workflows
Browse →Open the exact repair flow most commonly associated with P0430 on this vehicle.
Open the exact repair flow most commonly associated with P0430 on this vehicle.
Open the exact repair flow most commonly associated with P0430 on this vehicle.
Open the exact repair flow most commonly associated with P0430 on this vehicle.
Open the exact repair flow most commonly associated with P0430 on this vehicle.
Open the exact repair flow most commonly associated with P0430 on this vehicle.
Related Codes
The catalytic converter on bank 1 is not converting pollutants efficiently. This is one of the most common DTCs.
Bank 2 warm-up cat efficiency code.
General fault in the downstream O2 sensor on bank 2.
Frequently Asked Questions
- Why do I have P0420 AND P0430?
- Both cats failing together usually means something is damaging them — running rich, oil consumption, or coolant entering combustion.
- Can I use aftermarket catalytic converters?
- In many states, yes. In California, you must use CARB-compliant converters. Aftermarket cats are much cheaper than OEM.
Related Repair Guides
If your vehicle has triggered P0430, these DIY repair guides may help: