Quest engine stalls after fuel filter change

I had similar symptoms with my old Opel Insignia after messing with the fuel system. The check engine light indicated a pressure drop, and the engine would misfire. In my case, the issue stemmed from a faulty fuel pump relay. Did you check the fuel pump relay after changing the fuel filter? Maybe the fuel pressure is too low.

So, you're saying that the misfire could be linked to a pressure drop caused by a faulty relay? Is there a straightforward way to check the relay, or is it better to replace it outright?

Well, in my case, the relay was the culprit, but it could also be the regulator itself. A faulty fuel pressure regulator won't maintain the correct fuel pressure. Given that you suspect a connection to the fuel filter change, it might be wise to visit a workshop. They can properly diagnose if it's a faulty relay or the fuel pressure regulator.

I took it to a workshop, and it turned out the fuel pressure regulator was indeed defective, probably damaged during the fuel filter change. The repair cost was 45€ including the new regulator. Now everything runs smoothly again.