2001 Honda Civic "Check Engine" light

What exactly are the reasons that the Check Engine Light was triggered on my 2000 Honda Accord-145,000_miles?

if the car is starting and running fine and not overheating, don't worry about it until you notice something, then take it in for service. as for the service light, honda programms the computer to turn it on every 5,000 to 7,000 miles for oil changes. i don't know if this will work on a 2001 but it works on my 2004. get in the car and press and hold the trip counter button. put key in the ignition and just turn the key on and off on and off and while still holding the trip counter button start the engine. hold the trip button untill the light goes out. if this works and the light comes back on in a few days go for the service, if not, don't worry anymore!