..yes, as long you can hear the EGR manually open/shut...there could be the remote possible that the EGR diaphragm is not working, which will also give the code. You should hear it snap shut .

The ECU does not normally call for EGR at idle, so if you manually induce EGR air at an idle, what you are actually doing is creating a large vac intake leak..so the engine tries to stall [ same as if you were to pull off the brake booster vac line]
The engine will not completely stall b/c the Engine management will try to correct the lean condition, but it will run very rough. If the tube is blocked, then opening the EGR will result in no rpm change b/c the tube blockage allows no air from the EGR to reach the intake.
What code did you get? .. there are different flow specific EGR codes to pin-point the condition......