An improper fuel nozzle insertion-inhibiting assembly may include a cover having a nozzle inlet barrier door pivotally secured to the cover. The cover may include a safety-release groove that is configured to separate the cover into separate pieces upon exertion of sufficient force. A main body is secured to the cover and configured to connect to a fuel fill pipe. The main body may include a nozzle outlet barrier door pivotally secured to the main body. A debris filter may be secured to one or both of the cover and/or the main body. The debris filter is configured to prevent debris from passing into an internal chamber. A pivot-restricting member(s) may be secured within the internal chamber. The pivot-restricting member(s) is configured to prevent one or both of the nozzle inlet barrier door and the nozzle outlet barrier door from over-pivoting. At least one seal member may be configured to sealingly engage at least portions of the fuel fill pipe, the cover, and the main body.