My car: Audi A3 2.0 FSI Sport (2004/2005)

Well i'm getting the P2279 code and it says intake air system leak.

I've replaced both the black pipes that come from the rocker cover and removed the code but still getting it, what other pipes could it be? anyone had this problem before?

I have no idea what pipe it could be if anyone has any information on working out which pipe it could be or even point out the possible pipes it would be great. It might not be a pipe i've been reading it could be the PCV valve or something? but if you guys could have your input it would be great!