Skoda Fabia boost pressure control fault

Reduced engine power and a check engine light on an older Fabia could mean a few things related to boost. Since the vacuum switching valve is suspected, have the vacuum lines been checked for leaks? A leak could mimic a faulty valve. Is there any unusual noise, like a whooshing sound, when the turbo is supposed to be working? Does the engine stall?

I did a quick visual inspection of the vacuum lines, but didn't notice anything. I don't have a smoke tester. The 'whooshing' is hard to discern because of engine noise. How can I be sure it's the boost solenoid and not something else, like the bypass valve or a general vacuum leak causing compressor surge?

Those symptoms definitely point towards a problem with the boost control system. It could be the solenoid, a vacuum leak affecting its operation, or a sticky bypass valve. Without proper diagnostic tools, it's tough to pinpoint the cause. Given the age and mileage, a worn vacuum switching valve is plausible. It might be worth taking it to a workshop for a proper diagnosis. They can use a smoke tester and other tools to isolate the problem.

Just wanted to share that the vacuum switching valve was indeed the problem. A mechanic confirmed it and replaced it. The boost is back, and it cost 140€, but my Fabia is running well. Thanks for the assistance.