Mini Clubman Diesel Check Engine Light and Reduced Power

Check engine light and reduced power eh? I had something similar happen with my old Peugeot once, though it wasn't a temperature sensor specifically. It was also some kind of exhaust component. Is the temperature fluctuation really bad? Does it happen at certain RPMs?

Ah, uphill load making it worse, sounds like a probable leak. As I remember, the code pointed to the catalytic converter on mine, but it turned out to be a crack in the exhaust manifold. Exact same symptoms: check engine light, limp mode sometimes, and drinking fuel like crazy. Honestly, I'd take it to a workshop and get the exhaust system pressure tested.

The fluctuation seems pretty erratic. It doesn't seem tied to RPM specifically. It's more noticeable when the engine is under load, like going uphill. Your Peugeot situation sounds familiar – what exactly was the faulty exhaust component in your case? And what were the exact symptoms you experienced?

I took it to the shop. It was the exhaust temperature sensor, likely due to a small leak in the exhaust system. They replaced the faulty exhaust component, and the car is running smoothly again. Cost me 265€. Thanks for the input!