squawbum

Hey all. I have a persistent P0442 code that comes up every once in a while and it is really annoying. So far, I've changed the engine side Purge Valve, the fuel line vent valve and got a new gas cap. Still the annoying check engine light with code P0442 comes back every so often. So I finally did a smoke test, pumping in smoke from the engine side where the purge valve goes and used the durametric to close off the charcoal canister valve and no smoke. It was hard to see the smoke so then I pulled vaccum on the engine side tube where the purge value connects. I tested to make sure that I get no vacuum when the charcoal canister valve is open and that was so, Then I close the valve with durametric and can pull vacuum. I pulled about 20 Hg and left it there for more than an hour and the needle didn't move. It held vacuum totally. So the system is sealed and no leaks are present. The only variable is the cannister valve since the engine side purge valve is brand new from Sonnen Porsche-although, come to think of it, I've never really tested that either.

Is there anything wrong with my logic here or can I deduce that the system is sealed and that the canister valve has inconsistent sealing and causes a leak every once in a while and to change it?

Thanks in advance!

jayi836

Any update on the emissions slow leak?
Been getting the same code bon my 2011 Cayenne Turbo

squawbum