P0430 on BMW — Catalyst Efficiency Below Threshold, Bank 2
BMW
Verified1 source
1 source
- Official data (NHTSA)official_feed
What P0430 means
Caution — monitor closely
Bank 2 catalyst is below its efficiency threshold — on V-engine BMWs this often shows up alongside P0420 (bank 1) and typically means catalyst aging or downstream O2 sensor degradation.
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General information, not a diagnosis or repair instruction. Always confirm with a qualified mechanic for your specific vehicle.
Common causes
- Natural catalyst wear (bank 2)
What to check first
- Scan-tool catalyst efficiency test
- Check upstream/downstream O2 sensors
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