Hey my purge selenoid vlve did not throw a code for a long time. it did after a month of stalling so you dont have to have a code thrown at you. there is a easy way to check it which i described in my previous post. other way to check it would be disconnecting the hose that goes from the valve to your heat shield and see if you can feel the vacuum . if you can then its bad. but again those valves do work 60% of the time even if they are faulty so sometimes it would close how it supposed to and sometimes it would become stuck. you can try taking it out and cleaning it with some gunk cleaner , just spray some inside and it might help for a bit. but i know there have been many revisions of that valve because of this problem. so its recomended you get a newest part straight from the dealer. its not worth byin it from anywhere else cuz u might get older revision which will do the same thing after few months.