Skoda Superb diesel engine power loss

Reduced engine power and rough running on a diesel, especially with jerking and hissing, does sound like an airflow control problem. The intake manifold is a prime suspect. Has the engine management light come on? Have you checked for any error codes using an OBD2 scanner? That could pinpoint the issue further. The manifold flap is there to regulate airflow and improve engine performance, so if it's stuck or not responding correctly, it would cause the issues you are describing. I'd be curious to see what codes are being thrown, if any.

Thanks for the quick reply! Yes, the engine management light is on. I used an OBD2 scanner and got the error code P2015, which seems to indicate a problem with the intake manifold flap position sensor. Could this be related to the intake manifold flap control issue, or is it pointing towards something else entirely? Is there anything I can check myself before I consider taking it to a mechanic?

P2015 pretty much confirms the intake manifold flap issue. That code is almost always related to the position sensor giving incorrect readings because the flap itself isn't moving correctly or is sticking. While technically you could try cleaning the intake manifold and checking the linkage, given the mileage and the specific code, it's highly likely the intake manifold flap actuator or the manifold itself is faulty. For a model from 2020, it's a bit premature for such a failure, but it happens. Honestly, with that code and those symptoms, I'd advise getting it checked by a reputable workshop. They can properly diagnose the extent of the damage and replace the necessary components.

Thank you for confirming my suspicions. I visited my local workshop, and they were able to diagnose and fix the intake manifold flap control issue. It indeed turned out to be a defective switch, and the final repair cost was 465€. My Skoda Superb is now running smoothly again. I appreciate your help!