i haven't heard of anyone disconnecting the egr on the 2.5l (not that ive looked) but my understanding was that it was fairly common with the Chevy guys with tbi.. i don't know the effects (other than more power because your not running on exhaust)... to simulate blocking off the egr tube you can disconnect the vacuum line from the egr (make sure to plug the line you take off or it will be a vacuum leak when the egr is being told to turn on). so id give that a try first as its super easy to do and should show you the side-effects. wouldn't it be fairly easy to put a small bead of weld over the crack if you wanted to keep the egr intact.