S90 Knock Sensor Issue

That sounds familiar. I've got an S90 too. I had similar symptoms last year - check engine light, poor mileage, and rough idling. Did you scan the car for error codes?

Yes, I scanned it and got a knock sensor code. I'm wondering if it's a simple fix before I take it to a shop. Was it definitely the knock sensor for you?

Yep, the knock sensor was the problem. I didn't mess with it myself, just took it to my mechanic. Letting a pro handle it is probably best.

Thanks for the advice! I was hoping for a quick fix, but I'll book a service. I was quoted about 95€, so hopefully that sorts it.