The powertrain control module has detected a possible problem with the emission control system. Have your vehicle scanned for any trouble codes in order to repair the problem.
There are dozens and dozens of causes for the check engine light to stay on. You need to have the computer checked for codes to know possible causes.
check spark plugs and wires
you have a problem with your engine and and its emissions. take it to auto zone for a free check.
Check your gas cap.....My check Engine light always comes on if it is loose or not on at all.
Low fluid levels in engine.
Check to see if your gas cap is tight.
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.
There are pages and pages of causes for a check engine light. You need to have it checked for codes with a scanner to know what to diagnose. After the repair you can clear the code with a scanner.
The Check Engine Light (CEL) lights up when the Engine Control Module (ECM) detects a problem related to emissions or performance.
The engine is overheating. The check engine light is not on because you have no problem with the emissions system which this light monitors.
There are pages of causes, you need to have it checked for codes.
Your mom.