Mine stuck closed - got a CEL and could not pass an emissions test.

HOWEVER, a lot of the throttle delay was gone - I got a new valve put on, but then put a cutout switch in the car for when I want faster response. Using the switch throws a code, but once I set it back to normal, the code goes away in a few days.

If you read about the EGR, it is kind of a joke. It was implemented by the EPA to reduce one emission (can't remember - nitrous oxide??), but it decreases performance, it decreases mileage and increases hydrocarbon emissions.

On the Dragon, and in some other instances, I disable mine - combustion chamber temps will rise, but from what I read, not to any dangerous level, it's just that those temps work out to mean more of one emission (again, I THINK it's nitrous oxide).