Just make sure you do it properly. If your engine is strong, you should not have any problem. All the cars I have done EGR deletes, do not need to retard the timing unless there is some other issue with the car. Clean oil, good spark plugs and coolant and a good normal run, should be good to go and get it inspected. You are running cats? If you are and during the test the NoX is high, then retard it. That could be a lean tune, or deposits in the combustion chamber. Other wise you should be good.