P0456 - Evaporative Emission System Leak Detected (Very Small Leak)

WARNING: This page is about a different car, the 2007 Mercury Mariner and 2007 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.

P0456 - EVAPORATIVE EMISSION SYSTEM LEAK DETECTED (VERY SMALL LEAK)

Description:	The powertrain control module (PCM) monitors the complete evaporative emission (EVAP) control system for the presence of a very small fuel vapor leak. The system failure occurs when a fuel vapor leak from an opening as small as 0.508 mm (0.020 inch) is detected by the EVAP running loss monitor test.
Possible Causes:	Very small holes or cuts in the fuel vapor hoses/tubes Loose fuel vapor hose/tube connections to the EVAP system components EVAP system component seals leaking (refer to Possible Causes under DTC P0442)
Diagnostic Aids:	Check for loose or damaged vapor hoses. The evaporative emission system tester may be used to carry out the leak verification pressure test and leak detection smoke test.
Application		Key On Engine Off	Key On Engine Running	Continuous Memory
All		-	-	refer to PINPOINT TEST HX .