The EGR valve is not supposed to be open on idle at all.
If it is, you get crappy idle.
To check it, leave the car idling then disconnect the
EGR solenoid -> EGR valve rubber vacuum hose from the valve
and apply vacuum on it (you can borrow a handy vac pump from
autozone, or you can just plain suck on it a bit).
With vacuum applied the valve should open and the engine
stutter/stall.
If there's no difference, then the valve is stuck. Through cleaning
with intake cleaner might help, if not replace it.
If the valve is OK (and your idle improves after disconnecting
the EGR control hose) then either the solenoid (unlikely)
is bad or the DFPE sensor is dead (frequent problem).
In my experience 95% percent of idle problems are caused
by vacuum leaks / unmetered air though.
EGR system problems are usually come with a CEL.
Tiv
