The CEl stays on with my mystique. It's been that way for three years (nearly 60k miles during that time). I've reset it too many times to mention, and it always comes back on after 10-20 miles. I've had it checked at autozone, I've had it checked at Ford, and I've checked it myself with a multimeter. Nothing. No codes. I've kinda gotten attached to that purty li'l yaller light.

95 Contour Zetec, ATX (wrecked, sitting in the barn) 95 Mystique Zetec, MTX 2000 Taurus SEL 3.0L Duratec 1994 Crown Victoria LX 4.6 V8 1993 Chevy Silverado 4.3 V6