I recently had a new fuel pump installed in my 2000 Silverado (5.3 Vortec). About 2 or 3 days after the work was done, my check engine light came on. The code P0442 EVAP leak (small) is coming up. I've read many of the possibilities with this code, and it can be a bear to track down. But it doesn't seem like a coincidence that it came on 3 days after the new fuel pump was installed.

Any ideas?

The truck is running fine, no troubles at all.

 

Double check that any evap lines around the tank are snapped together properly. Make sure none of them were cracked. Make sure any hose clamps on the fill tube are tight.

 

could be the fuel pump connections weren't properly attached