How to Repair The Engine Code po456 And po440 On A 2002 Dodge Intrepid 6 Cylinder Engine?

Question

I have a 2002 Dodge Intrepid and needing to repair a check engine code of po456 and po440 by doing it myself, can someone help me by telling me how to fix this problem? I need to do it as quickly as possible so I will be able to secure a license tag.
I have exchange the Gas Cap and that did not solve the problem. I had the car checked out and was told that there is a very small leake in the Evac. system, I would like to know where to begin looking for the leake.

Answer 1

both codes are going to use the same diagnostics

I cut out the step you dont need or need a special machine (smoke machine)

You can check for broken,cracked or loose hose, by the engine bay and by the fuel pump see picture