Mini One check engine light air intake issue

Sounds like you might have an air valve issue. I had something similar with my Mini One. Check the hoses and connections related to the air supply. Manifold pressure could be off. Is it causing any idle problems?

Air supply hoses, you say? Any idea which one specifically? And how that relates to the throttle body?

Yeah, it was a small hose connected to the air pump. Caused some weird readings with the manifold pressure. I'd suggest taking it to a workshop if you're not sure. Could be tricky to diagnose properly.

Thanks, mate. Ended up being a defective hose connection from the pump to the valve, like you said. Cost 175€ to sort out.