Dropped off my S3 at dealers for service and drove missuses Leon FR 2016 home.

When accelerating hard-ish (no kickdown) there's a very noticeable hissing through from about 1800 until gear change, presumably turbo related. It's been a long time since I last drive the Leon so i cant tell if its down on power (compared to the S3 its a slug).

I have had a quick google and people have suggested its a pipe come off - But that means nowt to me, no idea where i would look and seriously doubt my skills can fix it.

Can anyone suggest what it's likely to be and the rough costs of fix?

Thanks all.