Ideal for 2013 Ford Flex Limited and 2012 F150. I wasn't sure if the throttle flap provided the proper seal to avoid the 'Check Engine' light and emissions system error code, and while this 'plug' is supposed to fit, I went to the hardware store and got one "O-ring" that slides over the inserted plug and acts as an airtight seal between the plug and the filler hole. Absolutely works as it requires a slight pressure when turning the key to the lock and unlock position. I think a 1-1/2" o-ring should be good and don't get a thin o-ring, you want to know it's doing its job. You want it to be very snug to the base so it doesn't These rubber rings are quite cheap so it makes sense to purchase additional products to have on hand if a new one is needed.