Check engine light has gone on the last 2 times shortly after I filled up gas tank…Could gas cap be defective?..What causes this light to go on?
There are at least a few dozen possible reasons the light may come on. A bad gas cap is just one of them.
What is the model year of this car? How many miles are on it?
The only way to tell what is wrong is to take the car to an auto parts store or a mechanic to get the codes read.
You could replace the gas cap to rule it out, but many auto parts stores will read the codes for free.
This vehicle is a Hyundai 2002 Accent…It has only 14,000 miles on it…Check engine light never went on before last month about a week after I filled the tank…Light went on again the second time, 6 weeks later as soon as I filled up again…Today I spoke to AutoParts Store and they will read codes for free…Thank you