Hey Guys. My SES Ltis on and the code is for a gas cap emiss. etc. on my 04 w/ 120k . New gas cap is on andtight.I removed the vent control valve and it seemed clean. Blew air through it anywho. I removed the whole black box (not sure of the name) and opened it. Didnt seem like a servicable item since it is plastic welded together. But I cut the seem and opened it. It has filters on both ends which keep the black bits inside it. Anyone know if the filters or black bits can be replaced or do I have to buy the whole assembly. Just had to find out what was inside. I am about to blow some air through the lines in the truck but isnt there a line that I shouldnt use air on? Thanks for your help again. NOT GIVING MY MONEY TO THE DEALERSHIP.At least I hope not to.