It could very well be an O2 sensor as well. Had it happen on my Contour at about 29K miles. Let us know what's up when you get it scanned. Also, does it smell funny when it's running, or right after shutdown?
'99 Contour SE V6 w/MTX (Black Clearcoat) '02 Dakota 4.7L V8 2WD X-Cab (Flame Red Clearcoat)
