A couple of weeks ago I filled my '95 Continental with fuel. Upon leaving the station I had to accellerate pretty hard to get into the traffic flow and my "Service Engine Soon" message lit up and stays on. I assume the culprit is the oxygen sensor. The car still runs OK (57,000 miles), so I'd prefer to stay out of the shop with it. How do I get the message cleared? Suggestions appreciated (I'm handy with minor repairs on both the car and the Cummins, but don't delve into things that require great technical abilities).