S90 Diesel Fuel Pressure Issue

I also own an S90, and your symptoms sound very familiar to an issue I experienced. The check engine light, stalling at idle, and reduced power all point towards a fuel pressure problem. Did you make sure the fuel filter was correctly seated and sealed after replacement? A small leak can introduce air into the fuel system, which can wreak havoc.

Thanks for the quick reply! Yeah, I thought I seated the filter properly, but now I'm second-guessing myself. What exactly was the issue with your S90, and what did you do to fix it? Was it the fuel pressure regulator itself, or something else in the fuel system?

In my case, the error was triggered by a defective fuel pressure regulator, as the error memory showed. While the fuel filter replacement might have triggered it, the regulator itself was the culprit. I suggest you have the car professionally diagnosed. A proper diagnostic scan can pinpoint the issue. While you might be able to troubleshoot some things yourself, fuel system issues can be complex. I ended up having to take mine to a shop.

Thanks a bunch for the advice! I took it to a local shop, and you were spot on – it was the fuel pressure regulator. They replaced it, cleared the error codes, and now it's running perfectly. Cost me 45€ for the part. Really appreciate your help in pointing me in the right direction!