Recently my gas cap has stopped giving me that satisfying "click" when I turn it, to indicate that it's tightly screwed on. Is that an issue? What happens if the gas cap is loose when I'm driving or parked?
If your gas cap is not tight then the computer will detect a leak and cause the check engine light to come on, or it may illuminate a "check fuel cap" light if your car is equipped with one. You may also have a fuel vapor smell in or around the car. I recommend having the cap replaced. You should be able to get a new one from any auto parts store or dealer parts department, make sure to get an OEM quality cap, as cheap caps often don’t fit right and may not seal properly. If you need help replacing the gas cap, you can contact a qualified professional, such as one from YourMechanic, who can do it for you. While they are out there they can perform an oil change if you’re due for one.