Strange Noise/Hesitation

[sgregory]

This is on an ea82 engine, when the rpm's are over 4k the engine will occasionally squeek for a split second and kind of hesitate, the check engine light also flashes on for a second. This will occur 2-3 times over the course of 30 miles or so. I'v checked the belts and they all seem tight. It has never done this under 4k rpm's. Any idea what this might be?