Random Throttle/Power Hesitations

[itsEz]

So the past few days I've been noticing some odd/very faint hesitations while accelerating. It's hard to describe the sounds I occasionally hear, almost like a wire rubbing a belt or something. The Z will also go from driving smoothly to faint skips like a heart beating fast and then returning to normal. Any ideas, the main change I can say is that about a week and a half ago I installed the gen 3 stillen CAI. Never had anything happen before, any ideas are appreciated. I've looked around the engine to see if I see anything loose or rubbing but hard to tell. What would cause the engine to feel like a slight loss of footing alllmost like a transmission slip/jerk but being a manual obviously not the case. Help my brothers!!