you can clear codes a couple ways. disconnecting the battery is one. if you have a code scanner iirc you just turn off the car during the koer tests and it will clear codes.

for the egr just leave it disconnected. your computer will eventually just override the code thrown by it. i did it so it works

 

alright thanks for info im going to go make me a block off plate to get rid of that egr, cause i think its going bad and i dont want to go buy a new one they are to much, as soon as garage gets a little warmer cause right now its like a freezer in there