Mini One exhaust noise issue

Interesting issue you're having with your Mini One. I have a similar Mini, and I experienced something comparable a while back. The louder exhaust noise and the error code definitely point towards a problem with the exhaust components. Have you checked the flap actuator? That was the culprit in my case. It's responsible for controlling the opening and closing of the exhaust valves. When it fails, the flaps can get stuck, causing increased exhaust noise and potentially triggering error codes. It might be worth inspecting before assuming the entire exhaust system is defective.

Thanks for your quick reply. Very helpful indeed! So, you mentioned the flap actuator. Is it easy to access and inspect? I'm reasonably handy with tools, but I do not want to start disassembling half the car without a clue. Any pointers on where to locate it and what to look for? Also, did you replace it yourself, or did you have it done professionally?

Yes, the symptoms you describe align perfectly with what I experienced. Given your mileage and the specific symptoms, a defective flap actuator is the most probable cause. While it might be tempting to tackle the replacement yourself, I would advise against it unless you're very comfortable working on cars. Accessing the actuator can be a bit tricky, and you might need specialized tools. In my case, I opted to have it done at a workshop. It saved me time and potential headaches. Plus, they were able to properly diagnose and confirm the issue before replacing the actuator. This might be the best course of action for you as well.

Just wanted to update you that I followed your advice and took my Mini to the workshop. Turns out you were spot on. The exhaust flap actuator was indeed defective. They replaced it, and the error is gone, the exhaust noise is back to normal, and the engine runs smoothly, even after a cold start. All in all, it cost me 190€. Thanks again for your helpful advice. You saved me a lot of unnecessary troubleshooting.