computer adjustments

I am new to this forum, and I see alot of guys making different changes to their trucks,(i.e. exhaust, intakes)> But I was wondering if there are any adjustments, or reprograms of any sort that need to be made to the computer systems of these trucks after such modifications. I bought my truck used about a year ago, it's a 97 Z71 Ext Cab with 144K miles. True dual 40 series flows, and a K&N air filter are the only mods that i can find, But my gas mileage really sucks, like 12 on the highway. Should something have been done at time of installation to compensate for the drop in gas mileage. Any suggestions would be appreciated!!

Help!! Any ideas at all?

I am new to this forum, and I see alot of guys making different changes to their trucks,(i.e. exhaust, intakes)> But I was wondering if there are any adjustments, or reprograms of any sort that need to be made to the computer systems of these trucks after such modifications. I bought my truck used about a year ago, it's a 97 Z71 Ext Cab with 144K miles. True dual 40 series flows, and a K&N air filter are the only mods that i can find, But my gas mileage really sucks, like 12 on the highway. Should something have been done at time of installation to compensate for the drop in gas mileage. Any suggestions would be appreciated!!

First, have you done or was a tune up done in the recent past? If not, that would be my first suggestion. Do you know what gears you are running, and are you running stock tires? A computer program would help your mileage out some, but we all know that the older 350s weren't exactly gas mileage friendly. I would say that is pretty close to what most normal 97 ext cab Zs should be at.