DTC P0456: EVAP System Leak - Very Small Leak: Condition
WARNING: This page is about a different car, the 2003 Suzuki XL-7. However, it is still accessible from the selected car via links, so may be relevant.
DTC P0456 is set when fuel tank pressure increase exceeds a predetermined value. MIL is illuminated when ECM detects malfunction during 2 and/or 6 consecutive drive cycles.