I just got a used Chevy 1500 and was wondering what I should do to it? My main focus is to get more MPG out of my truck, and I want to do that in a way where I am getting the most for my money and using it in the best/most effective way in acheiving my goal. I have saved up a pretty good amount of money, and I am already thinking about getting a cat-back exhaust system for my truck. With that said... What should be my next step? And what are the best brands?

Please, give me any help you can. And if you have any questions for me, feel free to ask!

Thanks!
Justin