When a check engine light comes on in your vehicle it's indicating that something is not right with your engine and is telling you the engine is having a problem and needs fixed.
It could be though something as simple as a loose gas cap or bad gas cap causing the check engine light to come on and in that case driving with the check engine light on is okay and your vehicle will suffer no damage if you drive with the check engine light on.
Other times the check engine light may be coming on because of an ignition system problems such as bad ignition coils, bad spark plugs, bad spark plug wires, bad ignition module, bad distributor cap and rotor or other electrical faults or cylinder misfire.
A bad catalytic converter is also another cause of a check engine light to come on because the bad catalytic converter can create back pressure on your engine which causes engine performance problems.
You can take your car to a place such as Autozone or Oreilly and they can do a check engine light test for free and let you know what is causing the check engine light to come on.