egr bypass, do you unplug the egr valve?

[hopeitlasts]

I have an 04 F250 with 65k on it. I just had the egr cooler, oil cooler, and radiator replaced under warranty. I am looking at installing an egr up-pipe delete from either RCD or Elite. Should the egr valve be left plugged in or unplugged, I have a welded egr valve should I use it? I don't want to do the full delete kit yet because my egr cooler was just replaced, and I am hoping by doing the bypass it will at least prolong the life of my egr cooler. It is a CA truck and I don't know what the FEDS have in store for us yet on emission testing so I would like to keep everything looking stock. Thanks for any help.