94Z28BLK

So i just installed my new computer and with it i had to replace my O2s cause the car was boggin' out. I assumed my AF ratio was way off and my car wasnt tuned for the EGR/AIR delete i did. ANYWHO- when i installed it the car took a few to adjust, but it ran smoother and was quieter. A day or so goes by and my car is back to screaming loud and sounds a lot choppier like it did before the tune. Wondering whats going on, or does my car just sound like a bat out of hell and thats the way it is (WHICH I LOVE). My issue is that the car just seemed smoother and better tuned during the 1st cruise after the install. What could the issue be? could there still be a AFR problem?
Thanks in advance
Mods are in my sig