Well, since all Ford could do was replace the sensors every couple weeks or so, I had finally given up on taking my 99 in for the check engine light. It runs a bit rich and fouls the sensors and there's no fix from Ford that I can find.

Well, I drove the truck for several years with that irritating light on all the time, so I finally broke down and bought an OBDII reader. I plugged it in and sure nuff, it was the sensors..so I reset the light, figuring I'd have to do it every week. Wrong. Evidently if the sensors get fouled enough, they wont register on the computer and turn the light on anymore. Ive driven several thousand miles since flipping the light off... and the truck still runs as good as new... and I'm not blinded by that danged light during nite time hours.