I am in the middle of diagnosing some issues with mine, one of which is bucking at WOT at aroung 3500 rpm. Almost every time.
In my case the problem was solved after changing plugs. I also fixed a leak at the maf at the same time (e o-ring on the maf was partially torn apart) but I dont think it is the maf that was causing the bucking because I still had the bucking when I swapped it for a known good one.
But you can still try cleaning or swapping the maf for a good one (borrow it from a friend), changing plugs, and also fuel filter.