Seat Exeo Knock Sensor Issue

That sounds frustrating! I had a similar issue with my old Opel Astra, although the symptoms weren't exactly the same. The check engine light kept popping up, and the car felt a bit sluggish. Did you check the wiring and connections to the knock sensor itself? Sometimes, it's just a loose or corroded connector, especially in older cars.

Interesting. When you say 'similar issue,' do you mean you also suspected the knock sensor? And did the Opel also exhibit rough idling or increased fuel consumption? I'm trying to understand if the symptoms were closely aligned, as a faulty knock sensor seems like a rather specific problem. What did you end up doing?

Yes, it was the knock sensor! The warning light was the main thing, plus it felt like the car was holding back. I cleaned the contacts, but the problem came back. My mechanic said it was a common issue, and he replaced the sensor, and that fixed it. Honestly, I'm not super technical, so I just let the pros handle it. I would suggest taking it to a workshop.

Many thanks for your input. It certainly pointed me in the right direction. After a bit more prodding and testing with a multimeter, I found a corroded connector on the knock sensor wiring harness. Cleaned it up, applied some dielectric grease, and the check engine light is gone. Idling is smooth again, and initial fuel consumption seems to be back to normal. Total cost: 95€ for the connector cleaner and grease – a far cry from a new sensor!