P0430Powertrain
Catalyst efficiency below limit (bank 2)
Where to start
The catalyst on the second half of the engine performs below the limit — the same as P0420, only the other bank of cylinders. Before replacing it, make sure the rear oxygen sensor is healthy and there is no leak in the exhaust: those are replaced far more often.
A code is not a diagnosis. It says which check failed, not which part to replace. Clearing it without repair only means the car will report it again in a few trips.
How to put together a report a mechanic will actually read
We have a detailed piece on thisFault code P0420: the catalyst or just a sensor
How the code is built
Letter — the systemPowertrain: engine and transmission
Common or the maker's ownGeneric code: the same on every car
Which part of the engineEmission controls: catalyst, EGR, fuel vapour
Number of the faultThe serial number inside that group — it does not say how serious the fault is
All codes in «Catalytic converter»
How the app helps
CarScan reads this code from your car through an OBD-II adapter, shows whether it is active now or only stored, names the module that reported it, and puts it into a plain-text report for your mechanic.