10 months later and still have the damn code! I replaced the vent shut valve located on the canister last year and nothing! so im back at it again trying to get this code out of my life!

 

So when you removed that valve, did you check it by applying battery voltage? I wouldn't replace a valve just because that was the one that failed on someone else's car. When this happened to me, I took off a couple valves until I found one that was NOT working.

I think you said you got code 90 but didn't get the OBD-2 code (1456 vs. 1457). Still true? If so, then you might even be looking at a bad gasket on your gas cap. Or a bad gasket on the fuel tank (fuelpump installation flange). You can narrow down your search by getting the OBD-2 code.