Seat Ibiza diesel engine trouble

Sounds like a similar issue I experienced with my Ibiza. Rough idling and a noticeable drop in fuel economy were my first clues. The check engine light followed shortly after. Have you scanned for any error codes? That would be the first step. It could be a faulty sensor, but the stalling points towards something more serious. When the 'check engine' light illuminates, the ECU (Engine Control Unit) has detected a fault within the engine management system. It stores a Diagnostic Trouble Code (DTC) which can be read with a scanner.

I did get a code reader on it, and it pointed towards a fuel regulator issue. I'm getting reduced engine power too. Is that consistent with what you saw?

Yes, reduced power is definitely consistent. In my case, the fuel volume regulator was the culprit. The high pressure pump was also on its way out. Given the symptoms and the error code you pulled, a visit to a workshop for proper diagnosis is probably the best course of action. They can confirm the fuel regulator and pump issues and give you a definitive solution. Don't keep driving it like that, you might cause more damage.

Thanks for confirming my suspicions. The workshop diagnosed a defective fuel volume regulator, most likely caused by a failing high pressure pump. Repair cost is estimated at 1510€. I authorized the work. At least the check engine light will finally go away.