Come to think about it, I got the P401 code - too little flow.
You may want to yank the electrical connector off the EGR and confirm the pins are not corroded, wet or gritty. Work the connector on and of 2 or 3 times to clean it and see if the light goes out in a few days.

Keep in mind an EGR stuck closed will give you quicker throttle response but make you unable to pass an emissions test. A valve stuck OPEN will slow your throttle response, and keep you from passing a test.