Your EGR problem as you describe it may be a DPFE sensor problem like mine was. Check your EGR valve before you replace it.
To test the EGR valve, get a length of hose from your local auto parts store that will fit over the EGR vac hose connection. Start the car, let it idle, unplug the vac hose from the top of the EGR valve, put your new length of hose on the nipple & pull a vacuum on the EGR valve (suck on the hose)
If the car continues to idle fine, you've got a bad valve. If it sputters (or even stalls) & you have to continue to apply more & more vacuum, you've got a bad valve.
If it sputters & you can keep it running rough by crimping the hose, then the valve is in good shape & your DPFE sensor may be ka-put - like mine was.
