Howdy! I'm about to hit 100k in my '12 Cummins 2500 and starting to research on what improvements I can do to help with mpg, performance etc. I googled "straight pipe exhaust" and was reading up on it and the site was a suggested site to join. My truck as of now is bone stock with the exception of a k&n replacement filter. I'm new to diesels and not really sure on where to start my work. Any suggestions?

Things I have heard to do:
1. Straight pipe exhaust
2. Delete EGR valve
3. Upgrade intake
4. Programmer

I cannot afford to do a lot at once, so I am trying to figure out the best way to approach one at a time. Any advice would be much appreciated. I have been browsing this site this morning and looks like some good stuff! I'm happy to be a member. Thanks in advance, guys!