Mini Roadster Engine Running Lean

A lean running condition could stem from several things, since you have the check engine light on, you should read the error code. But I had a similar issue on my Mini. Reduced power and jerking sounds like a fuelling issue. Before you go too deep, have you checked the usual suspects like your mass air flow sensor and whether the intake manifold is properly sealed? A faulty EGR valve can also cause havoc with the air-fuel ratio. When were the spark plugs last changed?

Thanks for the quick reply. I haven't checked the EGR valve yet. I replaced the spark plugs about 20000 km ago. You mentioned the mass air flow sensor and the intake manifold. Did you experience similar jerking when accelerating and reduced power when you had your lean running issue? And how did you diagnose the issue? Did you check the air-fuel ratio, or were there any specific error codes?

Yep, that sounds very familiar. I also had jerking and power loss with a lean running condition. Given that you've checked the plugs and it's still happening, and the error codes likely point to fuel trim issues, I’d seriously consider having the injectors checked. It’s not always easy to diagnose these issues yourself without the proper equipment. A workshop can perform a flow test on the injectors. Given your symptoms and mileage, it is probably the best course of action.

Just wanted to give a quick update: I took your advice and brought the Roadster to a workshop. Turns out, you were spot on with the injectors. After replacing them, the car is running smoothly again. The final bill came to 515€, but it was worth it to get the car back to its old self. Thanks again for your help!