hey i have an 06 sierra and i noticed that theres a hole just behind the throttle body on the intake. there used to be a port that connected a rubber hose to the valve cover but i took it to a shop and they installed a catch can i havent noticed it before until know how can i plug this is there a specific part number or plug size that i can put in there thanks...

 

anyone.....

 

Go to auto parts store, sort through the vacuum cap/plugs, find one that fits. You should be getting a MAF CEL with that port open.