I have a 2002 Audi A6 3.0L. I am getting error Vag codes 17819 and 17831 which are secondary air injection systems Banks 1 & 2 insufficient flow. The mechanic said it will likely be the PCV breather vent valve Part 06C103245. He hooked the Vagcom up and I could hear an air hissing sound coming from there so there is an obvious leak.

Can a broken PCV valve alone cause leak or do I need to change the hoses also.

What hoses should I change (if you have the part #)?

Where do you find the vacuum line hoses (part # and good place to buy)?