full non-seq w/ secondary compressor surge
 

I am full non-sequential for about two years now. Its been running great then here recently I have been noticing alot of compressor surge coming from secondary side of twins. Now I have checked my aftermarket bov which was doing fine. I took off and now I am running my stock one just to make sure. Still am noticing some surge. Any ideas?? Would worn turbos cause this. Anything at all would be great, have searched and searched with no answers.