P0456 The Key to Unraveling Evaporative System Mysteries

after a lot of diagnosis, we found out that Leak Detecttion Pump was the culprit. it was $25 part and the check engine light went away next day. This code means small leak in the evaporative emission control system, and it wasn't lying. After carefully removing the tank I found the cause of the gas leak. Need Help - Code P0456 EVAP Emission Control System Leak (very small). Jump to Latest. 51K views 15 replies ... Got the 0456 code and found out that it was the emission/ evap system "small leak." Most folks, including my mechanic suggested starting at the gas cap. P0456 Trouble Code Again (Evaporative emission control system small leak) ... Been to dealer twice for this Check Engine Code. First time charged ... Have you tried spraying the fuel door spring with some WD40 and exercising it? Sometimes it binds just enough to throw the code. Basically spray ... Your car's computer will set the P0456 code when it determines that there's a minor leak somewhere in the evaporative emissions control (EVAP) ... P0456 is a generic OBD-II Code that the engine control module (ECM) has detected a very small leak in the evaporative system during the vehicle off testing. A P0456 indicates a fuel vapor leak or lack of purge flow in the EVAP control system. It means a large leak has been detected. The EVAP system is detecting a very small leak from the fuel tank and lines. The evap system considers a large leak as a crack as big as the period at the end ...