DS3 Knock Sensor Issue

Knock sensor issues on the DS3, huh? Higher fuel consumption and uneven idling definitely point that way. Have you checked the sensor itself for any physical damage? Also, what kind of error code are you getting? That could help narrow things down further.

The error code is P0325! I visually inspected the sensor and didn't see anything obvious. What electrical tests can I run to confirm it's the sensor and not something else?

P0325 pretty much confirms it's the knock sensor or its circuit. If the wiring looks okay, and you're not confident in testing the sensor itself, honestly, it might be worth taking it to a workshop. They can properly diagnose it and replace the sensor if needed. Cheaper than guessing, and they have the right tools.

Workshop visit it is. The cable or plug connection was defective, the repair bill came to 95€. Better than a complete engine rebuild! Thanks again for your help!