I am pretty sure I was seeing a TPS/throttle icing issue last weekend. The powder was really light and deep and spraying up into my throttle block. First I felt the throttle lever being stopped from going all the way to the bars, so I cleaned it out from inside the lever. Then going down the trail I could feel the throttle not wanting to go all the way back when I let off, so I whammed the throttle back and it made it better. Next morning I fired it up and when I tried to give it throttle the engine light flashed and it idled back. After some looking on the bottom side there was a thin piece of ice that was wedged between the lever and the block and it was tricky to get it out of there. Now it seems good to go but definitely something to watch on deep days.