2002 grand prix check engine light

the check engine light just came on when the car turned 75,000 miles is this common or could i possibly have a problem car runs fine no changes in performance thanks for any input

A light at a certain mileage is not common. Take the car to an autoparts store like Autozone as they will scan it for free. Write down the code and post it here and someone will help you out. It could be anything from a loose gas cap to a bad O2 sensor. Only the code will tell us for certain.