volent

Hi, I have a 2012 Chevy Silverado Work Truck which has a P0442 EVAP small leak. I replaced the Purge Valve, Gas Cap and the Vent Solenoid held pressure and it still had the P0442. I did a smoke test on it and sure enough the fuel pump had a leak in the plastic. I replaced the fuel pump, put it back together and I still have a permanent Po442 stored with no check engine light on and no pending codes after 770 miles after clearing the codes. After 770 miles all tests have run except the evap. I cant get the evap test to run. I am really frustrated after all the work. Should I take it to the shop or invest in a bi directional scanner where I could turn the sensors off and on to see whats up. I appreciate any help. Thanks