Evap codes suck, I have a Evap performance code pop up about once a year. Yes on the EGR delete. You just buy the block off plate for the port in the head, unplug and tie the connection up and out of the way and on the rear of the manifold where the nipple comes out I cut the pipe and put a rubber plug over it with a clamp. Its nice how much room it opened up. I know all of that was done through the DSP, on the old motor I ran SCT but still had the EGR on the motor along with the cats so not 100% sure that will knock those codes out. Best thing would be to hit Sean up on your options with him.