Hello municipality, I am a proud owner of a Cupra 300 with the CJX engine for a short time. In the past days I have looked a little closer in the engine room, because I am very interested in technology. Now I noticed on the air filter box a thin hose, which runs off there. I have not had such a thing at any car that I had so far. I guess this tube takes off some underpressure there or something like that. Is here in the forum maybe someone representing me the sense and the radio From older cars one knows of vacuum connections e.g. from the ignition distributor for the vacuum box at the distributor. But what does this connection to the air filter box have for a function?? Thank you in advance Greetings Bernd