a8 4.2tdi BVN EGR or Swirl problem

HI,
numerous problems, but most immediate concern is strange whooshing noises from engine at low speeds accel/deccel
very low air mass on one side occasionally (frequently, when hot).
replaced MAFs, didn't solve.
the main fault indicated on vag-com is insufficient EGR flow.
sounds (I'm basing purely on guesswork really, no experience with V8 TDi complexity) like a swirl problem but no fault codes and both sides seem to operate ok.
EGR's both off, cleaned and very kindly checked by a friendly VAG specialist at no charge :-) they looked good and I don't think they are faulty.
if I disconnect BOTH EGRs the problem is "solved" but of course that is causing other issues.
on more detailed research (looking at elsawin and some audi training material I found) I'm now thinking blocked EGR cooler. before I spend loads (more..) on investigating I would like some experienced advice.
it looks like a part that could easily get gummed and stuck, so maybe off and clean could solve? or could the whooshing be a vacuum problem?
please help me before my wallet is empty (I know what I bought..... I factored some additional maintenance costs and plenty for fuel, but really......)

other fault is turbo 1 intermittent error, I'm pretty sure its age-old sticking vane problem, and I know what will be needed to solve that (turbo off, mr muscle clean, careful of seals and lines), but want to solve the other problem 1st.
and an A/C fault, will post seperatley if I need help.

I'm also missing some label files would be very helpful if someone could PM me 057-910-409-BVN1.lbl and 057-910-409-BVN2.lbl

thanks in anticipation