i have a 1996 4wd blazer that's showing and evap code: (p0440). it has been showing it for almost a year already and i never really noticed any problems. i recently made a 2000 mile trip (from mexico to canada) and in the last 200 milesit went from 21 mpg to 15 mpg. is it possible this is because of the evap code? how can i fix this?
i have new tires and spark plugs.

any advice would be really appreciated.

thanx

 

I would start by taking a look at THIS THREAD.

About your mileage change... Possibly picked up some water in your fuel? Clogged fuel filter? Bad fuel? Did you stay with the same brand fuel on the trip? Seeing as how 200 miles is easily covered in a single tank of fuel, I would be more inclined to believe that you picked up some bad fuel.