Unleash the Power How to Seal Evap System Leaks

2005 Ford Taurus 3.0 Vulcan engine. Auto Climate. New Evap purge valve under hood and vent solenoid on the canister, new Egr and tube (Old one broke, go figure) There are several things that can cause an EVAP Leak: · A bad seal on the gas cap - By not being be tightened properly and /or the gas cap itself ... First: Check your vacuum lines. It is most likely due to a split or dry rotted line. Next step: Check your fuel tank hoses and the purge valve ... Probably The Most Common Evaporative Emission Control System (EVAP) Code On A Toyota, P0442 Signifies A Small Leak Is Detected. The EVAP system basically routes gas fumes back to the engine (it's a closed system)to burn rather than venting them out and polluting the air. The only way the evap system can purge (into the engine) is through the purge valve. Otherwise it would just leak into the atmosphere. An EVAP system can have first check to see if the cap is tight and seals against the filler neck. Next remove the cap to inspect the cap O ring seal. Check filler neck, rubber hose from filler neck to tank, charcoal canister and associated hoses and such. A broken hose anywhere in the system ... A P0456 is a very small leak detected in the evaporative system. 99% of the time it's caused by a loose or bad gas cap. I would start by ... Check Engine Code Says EVAP? How to Diagnose EVAP System Problems and Leaks.