Spectra Premium Spectra Fuel Filler Neck FN958 Unit is designed to Original Equipment (OE) fit, form and function requirements Unit is dual coated for enhanced corrosion protection Fit tested on the very same vehicle application for which it was developed verifying first-hand that the design fits properly and can be easily installed Unit is leak tested after production to ensure product in free from fuel and / or evaporative leaks Tested with Original Equipment (OE) fuel cap to prevent EVAP and check engine light failure