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
2 answers 3 comments
ANSWER by on October 04, 2013
Have the evap system smoke tested to find the leak. While tank is half full!!!! or less.
COMMENT by on 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 on 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 on 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 on October 04, 2013
agree with #1