x-90 P0335 code

[CSUSBgeochem1]

Ok so now that you have pretty much all the info in pictures i wanted to let you know something i noticed while timing with the gun. After timing to 5 degrees, i removed the jumper to watch the timing advance as the throttle was increased. What i did notice was every time i would gas the throttle the timing would slightly retard, then advance. Like it would go back a little then move forward. I thought this kind of odd, like how can the crank timing retard slightly before advancing instead of just steadily advancing. Not sure if this is the misfire happening as im gassing the throttle but i thought i would mention it. Ill try and get some photos of it happening or video so you can see what i mean. Other than that im clueless. I need to invest in an oscilloscope but want the 2430 like you have.