Talisman check engine light air valve

Could be a vacuum leak. Check the hose connections going to the air valve from the pump. Manifold pressure can be affected by bad hoses. Are you experiencing any idle problems, or issues with the throttle body?

I haven't noticed any idle or throttle issues. Where exactly should I look for these hoses? I'm not very familiar with the engine layout.

Given that you're not familiar with the engine layout and haven't noticed other symptoms, the hose connection from the pump to valve is still a likely culprit, but honestly you should take it to a workshop to get properly diagnosed. These air supply problems can be tricky.

Okay, thanks for the help. I took it to a shop, and you were right. It was a defective hose connection from the pump to the air valve. Cost me 175€ to repair.