how to check for vacum leaks?

[ejhiggins]

How do i check for vacum leaks behind the intake manifold (pcv plate and hoses) is there any tools that i can use ? do i have to remove the intake manifold to replace the gaskets and hoses or can this be done with the manifold in place?

[Javier]

engine running and listen for changes in the idle speed.

[632 Regal]

e in idle quality.