Peugeot 408 check engine light

Sounds like it could be an air leak. Check your vacuum hoses, especially the ones connected to the intake manifold. A faulty hose connection from the pump to the valve could trigger that check engine light and maybe cause some idle problems. Any rough idling or noticeable loss of power?

Thanks for the tip! Where exactly is that hose connection located? I'm not super familiar with hybrid engine layouts. Is it easy to spot, or am I going to be digging around for hours?

It can be tricky to find on the 408 hybrid since it's a bit more compact. Honestly, if you're not comfortable tracing vacuum lines, especially with the hybrid system involved, it might be worth a quick diagnostic check at a workshop. Could save you a lot of frustration.

Yeah, you're probably right. Took it to a shop, and it was indeed a defective hose connection from the pump to the valve, like you said. Cost me 175€ to fix. Thanks for pointing me in the right direction!