SM5 NOx Catalyst Aging and Exhaust Leak

I also own a SM5. I had a similar issue with an exhaust leak and check engine light. It can be caused by leaks in the exhaust system, which messes up the readings from the sensors that monitor nitrogen oxides being processed by the NOx catalyst. Can you tell where the exhaust leak is coming from?

Thanks. I'm not sure exactly where the leak is. I only know basic car maintenance. Could even a small exhaust leak cause the NOx catalyst aging error? I'm trying to understand how the two are connected.

Yes, even a small leak can really affect your exhaust system's efficiency because the sensors are very sensitive. The leak lets in extra air, which throws off the combustion and the readings from the nitrogen oxide sensors. That's probably why you're getting that error. I'd get it checked at a workshop. They can find the leak and see if the catalytic converter is damaged.

Thanks for the advice. I took the car to a workshop, and it was a small leak in the exhaust system. They fixed it, and it cost 265€. The error is gone, and the car is running well again. Thanks for your help.