I know a answer to this one since i just messed it up and re-did this EGR stuff. If you take the header tube out. IT WILL throw a CEL code. Leave the header tube and EGR alone.
Just remove the smog stuff and plug the back of the heads and white and orange vacuum lines.
Again. Unless you have plan to tune the car. leave the EGR or your car will stall every stop light.