The most common cause is that the gas cap is not seating properly. If your gas cap is loose, re-seat it and wait two days to see if the light goes off, if it does not, see below....
There are pages and pages of things that can cause a check engine light. You need to have it checked with a scantool. Then the code can be diagnosed and repaired.
Your bad muffler might be part of the reason your check engine light comes on. Usually, your bad muffler causes something else to go wrong and that causes your check engine light to come on. Problems cascade.
Low fluid levels in engine.
Your mom.
The Check Engine light comes on when the ECU detects a problem with the emissions system. Seek professional help.
you have a problem with your engine and and its emissions. take it to auto zone for a free check.
The check engine light on a 2003 Honda Accord will be triggered when something on the engine is malfunctioning. To rid the check engine a light the ECU will need to be reset.
There are pages of causes, you need to have it checked for codes.
Have the code read, that will tell you.
A problem with the emissions system.
No, the check engine light does not come on because your gas is half way full. The check engine light will come on if there is a problem with the engine.
There are pages and pages of things that can cause a check engine light. You need to have it checked with a scantool. Then the code can be diagnosed and repaired.
If an check engine light does not come on it is a good thing. When your check engine light comes on, it means you need service done on your vehicle.