p0430
Moderate
Buick · SUVs
Catalyst System Efficiency Below Threshold (Bank 2)
Quick Answer
Error code P0430 on your Buick 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
Scan codes and check oxygen sensor values
2
Inspect catalytic converter for blockage
3
Test downstream oxygen sensor voltage
4
Check for exhaust leaks
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
Gaskets
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