DTC P1422: Fuel Tank Small Leak; DTC P1423: Fuel Tank Gross Leak [11/2016 - 10/2017]: Description
WARNING: This page is about a different car, the 2019 Toyota Highlander, 2018 Toyota Highlander, and 2017 Toyota Highlander. However, it is still accessible from the selected car via links, so may be relevant.
Refer to EVAP (evaporative emission) System DESCRIPTION