Your fuel filler cap is one component in your car that you handle regularly if you pump your own gas. It’s also known as the “gas cap,” and it’s that plastic cover that screws onto and off of your fuel inlet tube so that you can pump gas into your tank, and keep contaminants out of your gas once you’re done pumping. It also provides a seal for the fuel system so the fuel tank can pressurize for emissions testing. If the fuel cap is missing or does not seal properly, the Check Engine light will come on.

Replacement fuel filler caps must match the exact size of the original or the new cap will not seal correctly.

The fuel access door is opened | The defective fuel filler cap is removed | The new fuel filler cap is installed | The fuel access door is closed | The repair is verified and the vehicle is tested for proper operation

Your fuel filler cap seal is checked with every emissions test performed on your vehicle. It should last the lifetime of your vehicle, though a bad seal may mean it needs to be replaced. If your fuel filler cap is missing or leaking, replace it. If the Check Engine light is on, have one of our expert mechanics diagnose it.

Though you are not likely to risk any major damage from not having a proper fuel cap on your tank, it is something that should be replaced soon. If the Check Engine light remains on all the time, other problems can go unnoticed.