evap emmisson cannister on 2005 Lincoln Navigator

had engine lite on . took to ford dealer.said it was probably loose gas cap.they tested cap said it was good and cleared lite.3 days later i could notget gas into tank kept tripping nozzle no matter how slow i went and engine lite came back on.took it back and they said it was emmissons cannister.replaced it for 350 dollars.left dealer and went to put gas in but would not take it.i took it back and they checked the vent line and was plugged off with dirt dobber mud . they removed it and everything is good now. my question is the vent line supposed to be opened ended.they say yes/

Asked by for the 2005 Lincoln Navigator
Yes, it pulls the vapors from the fuel tank by vacuum back into the engine. Vent line should be tied back into the filler neck. This is one reason why you are not supposed to top off the fuel. You end up dumping it into the evap cannister. More than likely you did not need the emmissions cannister they replaced, you just needed to uplug the line. It will set codes all the time. Did you get your $300 back?
no i did not get my money back. As they all say computor shows.So i dont have any proof. If i had taken it to a mechanic that does not have a computor with lots of experience he would have went searching and found it. For as im concerned all these so called certified trained mechanics are a bunch of YA HOOS. They talk to you like your stupid. Once the warranty is gone you are SCREWED.