Peugeot 5008 diesel engine power loss

Sounds familiar. Had almost the same thing happen in my old BMW 3 Series. Reduced power, engine light... Drove me nuts! Have you noticed any difference in fuel efficiency or maybe any weird airflow noises? Could be the accelerator pedal module or the electronics inside the valve itself. That's what caused my problem back then. It's worth checking those things before diving into a full replacement.

Fuel efficiency does seem a bit worse now you mention it. Airflow sounds normal to me, though. Is the accelerator pedal module hard to check?

On the BMW, it was a pain to get to, buried under a bunch of other stuff. Honestly, unless you're really comfortable with car electrics, I'd get it checked professionally. If it is the throttle valve, replacement cost can vary, but it's usually not cheap. Better to get a proper diagnosis to be sure. Could save you money in the long run. If the accelerator pedal module is defective, it could send incorrect signals to the engine control unit. This can lead to reduced engine power, illumination of the check engine light, and decreased fuel efficiency.

Thanks for the advice! Took it to a workshop, and you were spot on. Defective throttle valve. Cost me 265€ to replace. Runs like new again.