[Brooks7.3L]

I got my chip in last and installed it , everything was working good.Then this morning on my way to work i pulled up at a red light and switched it from 80 performance tune to lope idle and the service engine light came on and i had no throttle at all. so i pulled into my work , and shut it off and restarted it and everything seemed fine. what could have caused that and will it happen again. thanks for any info 2001 f-250 with afe stage 2 and 4" tb