I have a 92 f350 with a 460 and 4x4. Whenever I go over 2,200 rpm for a few minutes, the check engine light comes on. But as long as I stay under that it seems to be fine. So when I drive it easy, the light doesn't come on. But when I go over 72 mph or 73 on the highway for a few minutes it comes on. I drive the highway almost every day, and it doesnt' come on it I stay under 70 mph. Any suggestions? Thanks, Kyle

 

The CEL is telling you your computer has codes stored. You'll want to pull the codes, which is easy to do, look at: http://www.broncodata.com/tech/codes.htm