G
p0430
Moderate
GMC · Trucks
Catalyst System Efficiency Below Threshold Bank 2
Quick Answer
Error code P0430 on your GMC Trucks means: Catalyst System Efficiency Below Threshold Bank 2. This is usually fixable — see the step-by-step guide below.
Affected Models
Likely Causes
  1. Failed catalytic converter on bank 2
  2. Faulty downstream oxygen sensor
  3. Exhaust system leak
  4. Engine misfire on bank 2
  5. Catalytic converter overheating
How to Fix It
1
Connect diagnostic scanner to check catalyst efficiency
2
Inspect bank 2 catalytic converter condition
3
Check downstream oxygen sensor voltage
4
Inspect exhaust manifold and connections
5
Replace catalytic converter if necessary
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
Exhaust manifold gasket
O2 sensor connector
Related Error Codes
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