Remove MAP and check if it is coated in oil. If so, check PCV. If needed, replace PCV (which is entire valve cover). I have a similar issue (same DTC) and this was the first thing VW dealership garage checked.
If none of these, try a smoke test to find a potential leak.
If still nothing, pull up a seat, this is one DTC that two dealership garages and an independent shop could not fix for me.