Chevrolet: 99 Cav Check Engine light?, cable modems, oil level

Question
Hi, Roger.  Hope you can help.  I have a '99 Cavalier, and as of this morning, she's running a little sick.  I started her, and the engine was running rough.  I think "jerky" might be a good word for it.  (It's been two days since I started her, no problems prior to this.)  I drove her for roughly three minutes before the check engine light came on.   Took her home, turned her off, waited five minutes, turned her back on (because maybe cars are like cable modems and just need to be power cycled ^_^') and the check engine light was still on.  Drove her around the block again - seemed to be running smoother but that light's still on.  I checked my fluid levels and found that the oil level was -really- low, about 3/4ths of an inch below the "Add 1 Qt." line.  This is going to sound stupid, but could this be the singular cause of the problem (Check Engine light and all)?  I'm trying to avoid having to have her towed to a mechanic and all that.

Answer
HI Kate;
     If the car is running fine, and it is not due for any
type of service,it could be a simple thing , as if the gas
cap is not even on right it can cause that light to come on. so if it goes out it should be ok but if not , it might be time for a service.
Roger