chek engine light stays on ,but drives fine. Good gas mileage , and runs normal temp.
If you post the code, we may be able to help.
most auto parts stores will scan your vehicle for free.
A problem with the evap system could turn the CEL on, but otherwise cause no drivability symptoms or engine problems; the only problem the owner might ever encounter, car won’t pass an emissions test. On the other hand, while a “too-rich” problem likewise could turn on the CEL w/no other symptoms, it could damage the expensive to replace catalytic converter more and more with each mile driven. So it’s in the owner’s benefit to at least take time to ask a shop why the CEL is on.
The light tells you there is a problem. It may not affect driveabilty or mpgs but you have a problem. A computer needs to be connected to the car to read what that code is so you can fix what is wrong. Or auto parts store will read them for free and give you the error codes. They likely are in the form P0123. If you have them read and post them here, we can help.