p0430
Moderate
GMC · SUVs
Catalyst System Efficiency Below Threshold (Bank 2)
Quick Answer
Error code P0430 on your GMC SUVs means: Catalyst System Efficiency Below Threshold (Bank 2). This is usually fixable — see the step-by-step guide below.
Affected Models
Likely Causes
How to Fix It
1
Inspect catalytic converter condition
2
Test downstream oxygen sensor
3
Check for engine misfires
4
Scan for exhaust leaks
5
Replace catalytic converter if needed
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
Parts You May Need
Catalytic converter
Oxygen sensor
Heat shield
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