Admittedly an AI overview but it makes sense.

Yes, a new catalytic converter needs a proper break-in, often involving a specific driving cycle or heat-up/cool-down period, to seat the internal matting correctly and allow the car's OBD-II monitors to reset, which is crucial for passing emissions tests and ensuring it functions optimally to meet regulations. Failing to do the break-in can lead to reduced flow, premature failure, or issues setting the readiness monitors needed for inspection.

Richard

2018 Roadster 3.7
1966 Land Rover S2a 88
2024 Royal Enfield Guerrilla 450
1945 Guzzi Airone