Peugeot 807 Boost Pressure Fault

I had a similar problem with my 807. Reduced engine power is very unpleasant, and the increased fuel consumption even more so. Did you notice any compressor surge? Is there a noticeable pressure drop? Have you checked the boost controller or the boost solenoid?

Thanks for the quick reply! I haven't specifically logged compressor surge or pressure drop, but I can try to get some data. When you say boost controller or solenoid, was it visibly damaged, or did you just replace it?

I did not investigate it myself. I simply went to the workshop and let them fix it. It was indeed the boost solenoid. My advice would be to get your car checked out at a professional workshop.

Took your advice and brought it to the workshop. It WAS a defect in the vacuum switching valve, just as I suspected. New valve fitted, and the boost is back where it should be. Cost me 140€ all in. Thanks for confirming my suspicion!