Cylinder 1 EGT drop out

More recently, my cylinder 1 EGT has been reading incorrectly from time to time. Yesterday I flew it 2 hrs away and it ready perfectly in line with all the other cylinders the entire way there. The Entire way home however it would be reading in line with the others and then slowly drop until I would feel a brief hiccup Then the lane B light would begin to flash and the cylinder 1 EGT reading would become X'd out. I had experienced this two or three times prior but it seemed only on very cold days and a reset of lane A would bring it back for the rest of the flight (although often at a lower reading than the other cylinders). Any Suggestions as to where I should go from here? Sensor?