my check engine light goes on and then off some days, but the car isn't giving me any problems. I have a 2004 Acura MDX with over 100,000 miles on it.

 

Hello! welcome aboard!

Even tho you might not think the car is having problems, the check engine light is like a clue. it will give insight on what is going on with the vehicle, as the car is FULL of sensors.
Have the check engine light checked at your local parts store like Autozone. It's free to diagnose this CEL(Check engine light) , unless you live in California