Does the kitchen flue pipe affect the back door?

This is not good, it affects wealth, and it is very unlucky in feng shui.

The flue can't be changed without permission. As the property of the whole building downstairs in the same unit, the flue is shared by everyone and has no right to transform it. You can block the door of the original kitchen, then open one in the other direction of the kitchen, make them parallel, and make a partition in the middle of the opposite side.