Regarding the EGT sensor, if I haven't run the engine for 4-5 days when I startup the left side sensor almost always shows the red cross or a very high overtemp condition on my screen. I have learned to ignore it because in a few minutes of warmup it starts reading correctly and stays correct for the rest of the day. I have taken it out and cleaned it and checked the wiring but it has continued to do this for several years now. Probably should replace it; the right side never acts up.