We have heard of this unfortunate and easy to make mistake. You want to take care of your truck and use products that can help promote good fuel quality and system integrity which includes a variety of fuel system additives. Typically these products come in small bottles that have caps containing a coated cardboard disc inside of the cap intended to provide a seal.
Apparently these discs are not adequately secured to the cap and may remain stuck to the top of the bottle. If you are not observant and begin pouring your product into the fuel filler of your truck and this seal is stuck to the top of the bottle it may come loose as soon as the liquid begins to flow taking the cap into the fuel tank along with it. So what you say and there is probably all sorts of junk floating about inside you fuel tank? Well, there have been many reports of 2011 and newer Super Duty trucks that have been stopped in their tracks when these seemingly harmless discs get pulled up against the fuel pick up causing a restriction resulting in low fuel pressure and an engine stalling event. When this happens there will be a loud whining sound coming from the fuel supply pump and a low fuel pressure warning on the instrument cluster. This condition will likely be an intermittent and random concern making it very difficult to verify and diagnose therefore you should keep this in mind. And for the vehicle owner reading this, remember to look at your additive bottle before pouring. It just may save you and a technician some headaches.