Codes p0171 and p0174

So my check engine light came on in my 2002 330xi so i scanned it to see the problem and these codes p0171 and p0174 came up. It not my MAF sensor im pretty sure that it's a vaccuum leak. Any suggestions where the leak might be? Also, the box attatched to my intake manifold sounds like it might be the problem. Im not sure what its called but i know it as the breather box. The only effect on my car is that it idles very low and seems bogged down.