I unplugged the EGR when I did the service the other day. After a short drive, the light stayed off. I disconnected the battery to do another task, when I reconnected it, the engine light came on, read the fault codes and it was multiple EGR-related faults. Switched the light off, went for another drive and the light stayed off. Next time I drove, the light was on from startup. So yes, disconnecting the EGR will make the engine light come on. Have not noticed any difference in driveability although have not driven far. Idles better when cold and doesn't do the near-stall thing 10 seconds after cold start. No dakadakadakadaka noise when switched off, of course.
I think I will be reconnecting it.

