P0442 EVAP small leak. On the Trailblazer there is another item for that leak. They develop a leak at the fuel sender. This might even be a warranty item as it is emissions and you appear to be in the extended warranty that GM issued on the Trailblazers. I'd give a dealer a call and ask. Might not cost you a dime.
As for the vent valve it's under the truck on the frame rail.
Monday, February 27th, 2017 AT 12:39 AM