2007 Tahoe code P0455 on 2007 Chevrolet Tahoe

I have a 07 Tahoe. Recently the CIL came on with code P0455. The gas cap looks fine. I changed the Evap Solenoid, reset the CIL and it comes back on when the gas tank gets half empty. I tried another gas cap. No luck. Any suggestions next?

by in San Jose, CA on October 03, 2013
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2 answers 3 comments
ANSWER by , October 04, 2013
Have the evap system smoke tested to find the leak. While tank is half full!!!! or less.
COMMENT by , October 04, 2013
Any good way for me to do the smoke test or is this a dealer thing. What do you think about the fuel tank pressure sensor?
COMMENT by , October 04, 2013
It needs to go to A repair shop, not necessarily the dealer for testing and repair!!! Smoke machine and a professional scanner needed for ACCURATE test!
COMMENT by , October 04, 2013
One last thing....I also notice that when I pump gas, it stops numerous times making it hard to fill the tank. Any indicator of how that is related?
ANSWER by , October 04, 2013
agree with #1