I have a 2002 S80 with only 1k miles. The car is great except for one problem: the check engine light has come on twice in my short ownership. The first time it came on with 400 miles on the odometer. I took it to the dealer: the code was intermittent misfire. The dealer checked everything, including plugs, and said all was perfect. That was about three weeks ago. Today, while driving on the highway, the light came on again. The car drives very well, and I can detect no problem in performance. I live 60 miles from my dealer, so I cannot keep going there just to check on this light. Here are my questions:
1) What could the problem be? (It is not fuel or filling the tank which is causing this)
2) Is there a way to reset the check engine light?
3) Is there a device I can buy to monitor the code myself?
The car is wonderful except for this one issue. I appreciate your insight.

And I thought they were supposed to get better with the later models. I lost track of how may times I've brought my 99 to the dealership. I can't even sell the thing without giving it away. Take it to the dealership, fix it and trade it for a reliable car, like a Honda.

I had the same problem with my car at 8,000 miles. The problem in my car was an intermittant pedal sensor failure. The sensor was replaced, and I have had no problems since with the check engine light.

You'll have to return the car to the dealership as no other place or device can help you. If it were at my dealership considering a 2nd time and with so few miles, you'ld be given a free loaner car and your car would stay until the cause is identified and repaired as that's unusual for a new car.
All I can add is try to be as understanding as possible as I'm sure they'll go the extra mile to solve that problem for you.