OBD-II CODE / Catalyst
P0430 · Catalyst efficiency below threshold, bank 2
The catalyst monitor reported efficiency below its threshold on bank 2, the bank opposite cylinder 1.
Part of the Catalyst system guide.
Which side is bank 2?
Use the engine’s cylinder numbering. Bank 2 is the side opposite bank 1. Sensor 2 means a sensor position, which is a different part of the scan label.
One bank or both?
If P0420 and P0430 appear together, ask whether a shared mixture or misfire issue could explain both results. With a bank 2 result alone, compare operating conditions and investigate bank-specific leaks and sensor evidence before calling the converter.
Check for vehicle-specific guidance
On some 2018–2019 Volkswagen Atlas 3.6L vehicles, the OEM specifies a hardware and calibration repair for this code. Other engines need their own diagnostic procedure.