C2 engine stalling

Sounds familiar. I had a similar issue with my C2. Check the activated charcoal filter; a defective one can cause all sorts of problems with the fuel tank ventilation system. Has the purge valve been checked?

Charcoal filter, eh? Where exactly is that located, and is it easy to get to? And no, I haven't checked the purge valve yet. Is there a way to test it?

It's part of the emission control system; usually near the fuel tank. Honestly, it's a pain to get to without a lift. As for testing, you can try blowing through it, but you're better off taking it to a workshop to diagnose the system failure properly.

I took it to the workshop, and you were spot on – the charcoal filter was knackered. Cost me 275€, but it's all sorted now!