Same as P0420 but for the Bank 2 catalytic converter. On V-engines, each bank has its own catalyst. If both P0420 and P0430 are present, a common cause (ongoing misfires, rich/lean condition) has damaged both catalysts.

• Worn catalytic converter on Bank 2
• Engine running rich or lean
• Contaminated catalyst
• Faulty downstream O2 sensor on Bank 2

• Check engine light
• Failed emissions test
• Slight sulphur smell

1. Same approach as P0420 but for Bank 2
2. If both P0420 and P0430 are present, investigate common causes
3. Check Bank 2 downstream O2 sensor

Replace the Bank 2 catalytic converter after fixing any underlying issues.

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