My pressure plate recently fell apart, so I replaced my clutch with an Exedy Stage 2 Cerametallic and went ahead and put a new friction plate on my Fidanza flywheel. Recently (after about 75-100 miles on the clutch) the steering wheel started shaking on deceleration. By shaking I mean it jerks left and right like it would if I had warped rotors and were applying the brakes.

To make it happen, I push the clutch pedal to the floor and hold it, it'll start shaking, then I can let the clutch out in gear or not and it will shake all the way to a stop or until I apply any throttle. Is this just a side effect or is something wrong?

My setup is a 2000 Si with a '98 JDM Type R complete swap.