Q&A for How to Install a Gas Cap

Go on eBay and put in the year, make, model, etc. of your vehicle; see what part numbers come up. Then, you can buy there or use that part number to purchase the part anywhere that sells it. You can also take your old cap, hold it next to a new cap, eyeball the black O-rings (if you've got good vision), and see if they're a match. You can also take the O-rings out and lay them on top of each other to make sure they're close to identical. Then, screw the new cap onto the car to see if fits without issue. If so, put the rubber O-ring back on the new cap.

Remove the leash from the old gas cap and install it on the new one. Then install the new cap on the vehicle.

To remove the gas cap leash, use a pair of cutters to carefully cut it off.

Go to a hardware store, and they can help you find the correct size screw.