DTC P1422: Fuel Tank Small Leak; DTC P1423: Fuel Tank Gross Leak [02/2014 - 11/2015]: Description
WARNING: This page is about a different car, the 2016 Toyota Highlander, 2015 Toyota Highlander, and 2014 Toyota Highlander. However, it is still accessible from the selected car via links, so may be relevant.
The description can be found in the EVAP (evaporative emission) System.
Refer to DESCRIPTION