First let me qualify this by saying I know this isnt an eco-friendly green gas sipping hybrid car... It's a SUV.. I didnt buy it for the gas mileage... Now that we have that clear

I recently installed a Volant cat back exhaust system and GM Performance intake system. Prior to this, i was getting a steady 17-17.5mpg... after installation, I can't seem to get more than 13mpg ! I'm completely positive the driving habits havent changed (i.e. foot to floor to hear the sounds). I even blamed my wife for driving it like Richard Petty but when we swapped vehicles (H3 is family car) I couldt get the MPG any higher.

My only thought was I didnt reset the computer post install, and was looking for some advice... should it get reset after these ?

Other than that, my next step was to order an upgraded PCM.

Thanks