Seat Arona engine issues

The symptoms you describe certainly suggest a fuel-related issue. The check engine light, stalling, and power loss all point in that direction. Given the mileage, a failing fuel regulator isn't entirely unexpected. However, have you checked for any other potential causes, such as vacuum leaks or faulty sensors? These can sometimes mimic fuel delivery problems. What diagnostic trouble codes are showing up?

Good point about the vacuum leaks and sensors. I haven't specifically checked those. Where would you recommend starting to look for vacuum leaks? Also, I'm getting a P0087 code – Fuel Rail System Pressure Too Low. Does that reinforce the fuel regulator suspicion or still leave room for other possibilities?

That P0087 code, along with your other symptoms, does strongly suggest a fuel delivery problem and points to the fuel pressure regulator. While it's still possible that a sensor is sending incorrect data, the regulator itself is a more likely culprit. Given the potential complexity of the fuel injection system on the Arona, I would advise taking it to a qualified workshop for diagnosis. They'll be able to confirm the issue and advise on the best course of action.

Just reporting back on this fuel injection issue. It turns out the high pressure pump was the problem. The fuel volume regulator was defective because of it. Cost 1510€ to fix. Runs great now, thanks for the help.