Hi, thanks for the question and using JA.
The dtc P1456 stands for a leak in the Evap system for the gas tank. This is the code that comes up the most when you leave the gas cap off or the cap isn't tight enough. What you can do is tighten the fuel cap and then reset the ECU by removing the Neg. battery cable for a couple minutes. Then reconnect it, the light should be out and moniter it for a couple days. If the light never comes back then it's probably fine. If not it will need to be diagnosed further. I know this seems too simple but it's exactly what we do at the dealer, we just use a scantool to clear the ECU. If it comes back a week or so later we diag. it further.