knock at 90-95mph

[turbojitsu85]

I took the car out on the highway the other night and when I got the car up to around 90-95mph I saw about 2 degrees of knock with anything above 5psi of boost what could cause this and what would I do to fix it?

 

[WFO]

put a scantool on it and check your o2 #'s.i bet you're a little lean up top.

later,sean