C5 Manifold Pressure Sensor Fault

Greetings. I have a C5 with a similar diesel engine. My experience echoes yours. The symptoms strongly suggest a manifold pressure sensor malfunction, potentially triggered by a vacuum leak. Have you inspected the vacuum lines for any visible damage or disconnection? Furthermore, consider examining the sensor's electrical connector for corrosion or loose wiring.

Thanks. I'll check the vacuum lines and connector. Could a small leak really cause all these issues? Is there a way to pinpoint the leak's location without special tools?

Indeed, even a minor vacuum leak can significantly disrupt the engine's air-fuel mixture, leading to the observed symptoms. Without specialized equipment, locating the leak precisely might prove challenging. However, a thorough visual inspection of the vacuum lines, focusing on areas near connections and bends, is advisable. In my opinion, it is advisable to seek out the opinion of a workshop.

Thanks for the insight. I took it to a workshop, and you were right – it was the manifold pressure sensor! Apparently, there was a decent-sized vacuum leak as well. New sensor and vacuum line repair cost me 235€. Runs like new now!