Seals off your fuel tank and prevents contaminants in your Gas Supply Plays an important role in the EVAP system Easy to replace on your own The Fuel Tank Cap on your Nissan isn't commOnly talked about. You take off the Fuel Tank Cap, fill your vehicle's fuel tank, and then tighten it back into place each time you fuel up, but that's probably the Only time you think to acknowledge your fuel Cap. Your Fuel Tank Cap has a big part in the overall function of your Nissan. Obviously, it seals off your fuel tank and stops dirt, Water, and other harmful debris From seeping into your fuel. But here's another thing: the Fuel Tank Cap is also part of your Nissan's evaporative emissions system (or EVAP). When your engine is running, your fuel heats up significantly and releases dangerous byproducts. But, w/ a properly working Fuel Tank Cap, the EVAP system helps Capture those fumes to keep them From seeping out and contaminating the surrounding atmosphere. If your Fuel Tank Cap doesn't make clicking sounds when it screws onto your fuel tank, or if it frequently loosens even after you've tightened it completely, you're likely dealing w/ an old or damaged Cap. Since this component is also part of your EVAP system, your dashboard engine light may illuminate if your Cap is faulty. Other indicators of a worn out Fuel Tank Cap include strong GasoLine odors while you Drive and decreased fuel efficiency w/ no significant change in your travel behaviors. ConSider the downSides to a Fuel Tank Cap that has cracked or worn down. A Fuel Tank Cap that doesn't Fully seal can release harmful emissions into the air around your Nissan, but it may also create costly wear and tear inSide your Nissan and its engine. A worn out Fuel Tank Cap can decrease engine performance, tank your Gas mileage (no pun intended!), and cause fuel leakage. It's wise to replace your Fuel Tank Cap immediately once you notice that it isn't sealing or tightening properly. Replacing a damaged Fuel Tank Cap couldn't be easier, and you don't need special tools to do it. All you need to do is shop w/ Nissan directly to get a seamless fit for your vehicle. This Fuel Tank Cap (reference number 17251ZZ62D) is compatible w/ Nissan Armada 2011-2013, Nissan Frontier 2007-2020, Nissan NV1500 2012-2020, Nissan NV2500 2012-2020, Nissan NV3500 2012-2020, Nissan Pathfinder 2011-2012, Nissan Titan 2011-2020, or Nissan Xterra 2011-2015. See the What This Fits tab for additional information. Fits Armada, Frontier, NV1500, NV2500, NV3500, Pathfinder, Titan, Xterra All. Crew cab. 5.6L, 4 Door. Incl.Tether. From 08/2011. Bed Length 59.5".