Safrane Stalling Idling Low Power

I had similar issues with my Safrane, and it was a pain. Is your fuel efficiency also tanking? Did you notice any engine misfires before the filter change? It could be a pressure sensor issue. What about the fuel pressure itself - did you measure it?

Fuel efficiency definitely took a hit. Didn't measure the fuel pressure directly, no. The engine misfired a couple times, yes. But could a faulty fuel regulator really cause all these problems? Is it possible that there's a pressure drop somewhere?

A faulty fuel regulator can cause all sorts of mayhem, especially with modern engine management systems. If the pressure is off, the engine won't run right. Considering you changed the filter and then this started, maybe you upset something during the process. I'd go to a workshop and have them check the fuel pressure regulator and the pressure sensor right away. You will be suprised how quick the repair is.

Turns out you were spot on. The fuel pressure regulator was indeed defective, likely damaged during the filter change. New one cost me about 45€, but now the car runs smoothly again. Thanks for pointing me in the right direction!