The EGR was used for lowering combustion chamber temperatures by diluting the intake air with spent combustion gases (for the purpose of avoiding creating NOx combustion by-product)... this also has the side-effect of dirtying up your intake manifold... yech.

GM has long since figured out how to lower CC temps (and NOx) by other means (timing and fuell).

If your annual vehicle emissions inspection does not force you to have it, then delete is as Doc said.