Seat Inca diesel engine issue

Stalling at idle and a check engine light? Sounds like a pain. Is the engine struggling to breathe, like there's a vacuum issue? Have you checked the air flow around the purge valve? Could be a blockage somewhere in the EVAP system. Maybe even a faulty fuel tank pressure sensor messing things up.

Could you elaborate on how to check the air flow around the purge valve and what readings I should expect from the fuel tank pressure sensor?

Alright, so checking the airflow isn't super straightforward without tools. You'd ideally use a smoke machine to see where air is leaking. But visually inspect the hoses connected to the purge valve for cracks or disconnects. As for the fuel tank pressure sensor, you really need an OBD2 scanner that can read live data to see the pressure readings. Honestly, given the symptoms and your suspicion of the charcoal filter, it might be worth getting a professional diagnosis. A faulty filter can definitely cause those issues. They probably have the right tools to pinpoint the leak in the EVAP system quickly.

The workshop confirmed a defective activated charcoal filter. Repair cost was 275€. Problem resolved.