Saxo check engine light and stalling

Sounds familiar. I had a similar issue with my old Opel Astra. Check engine light, rough idle, the works. Turned out to be a problem with the fuel tank ventilation. It could be a defective activated charcoal filter causing a leak in the EVAP system. Does your fuel efficiency seem lower than usual?

Lower fuel efficiency, possibly? How can I check the charcoal filter myself? Is it difficult to get to?

I wouldn't recommend messing with the charcoal filter yourself unless you know what you're doing. On my Astra, it was a pain to get to, and you risk damaging other components. Plus, you'll need to clear the check engine light afterward. If it is the charcoal filter, better take it to a workshop. They can properly diagnose the leak and replace the filter.

Thanks for the advice! I took it to a workshop, and you were right – it was a defective activated charcoal filter in the fuel tank ventilation system. Repair cost me 275€, but at least it's fixed!