Seat Arosa engine light and stalling issues

I also own a Seat Arosa, though I can't recall the year. I had similar issues with the check engine light and occasional engine stalling. Have you checked for any vacuum leaks? In my case, it was a small crack in one of the hoses connected to the air valve. That caused the manifold pressure to fluctuate and triggered the error.

Thanks for the info. Where exactly is this air valve located, and how easy is it to check the hoses? I'm not very experienced with car repairs, but I'm willing to take a look myself.

The air valve is usually located near the throttle body, connected by a few vacuum hoses. It's fairly easy to spot. You can check the hoses by visually inspecting them for cracks or listening for a hissing sound when the engine is running. However, if you're not comfortable working on it yourself, it might be best to take it to a workshop. Vacuum leaks can be tricky to diagnose, and it could also be something else entirely.

Took the Arosa to a workshop, and it turned out to be exactly what you described: a defective hose connection from the pump to the air valve. Repair cost was around 175€. Thanks for the help!