Well, my '97 Explorer with the 5.0 and 90k on the odometer needs help. It has been stuttering the last few days, mostly at idle nad the tach hasn't dropped below 900-1000RPM. And while accelerating it has stuttered some. My first thought was bad gas, clogged injector maybe. I put in some better gas and ran that, and it went fine. On the way to work today, the problem starts again, and the check engine light is on. So, maybe an O2 sensor? My dad suggested maybe a spark plug problem. Any ideas?