You could have ethanol in the fuel, you can change the sled to the ethanol setting (which changes the fuel map), and the DET will go away.... same thing happened to my sled on the weekend at low elevation... I also happen to have a high compression head, which makes it even worse...
I'm looking forward to getting it stuck further into the trees this year! You need to get out with us a few times this year, we will keep you posted...