P0430Gmc Hummer-evYears: 1996 - 2026
Catalyst System Efficiency Below Threshold (Bank 2)
Reviewed by ASE Certified Technician
What does this mean?
Code P0430 is identical to P0420 but affects Bank 2 of the engine. The catalytic converter on Bank 2 is not cleaning exhaust gases effectively.
Disclaimer: This diagnostic code is part of the standard OBD2 system and can apply to Gmc Hummer-ev models manufactured from 1996 to 2026. However, please note that the presence of this specific code depends on your vehicle's exact engine configuration, options, and production year.
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Common Causes
Failing or clogged catalytic converter
Faulty oxygen (O2) sensor
Exhaust leak before oxygen sensor
Worn or fouled spark plugs
Clogged or faulty fuel injector
Symptoms to Watch For
- Check Engine Light is illuminated
- Rotten egg smell (sulfur) from exhaust
- Failed emissions test
- Decreased fuel economy