I have a 2012 octavia vrs 20 tsi .  on the side of the inlet manifold there looks like a advance and retard mechanism this keeps popping out when the throttle is opened up and loses major power and starts spluttering and virtually stalls. Is there a fix for this or does the manifold have to be replaced. Also since this the engine management light has come on with a p2015 error code.  Any ideas out there ?

Pretty sure you're describing the swirl flaps.

 

I haven't got a TSI but I believe it's a common fault, not sure if there is anything that can be done apart from replacing the inlet manifold.