Do I NEED A TUNE
 

I have a 1995 trans am with jaspers rebuild motor. The bolt ons are as follows, CAI 90 degree elbow, air foil, throttle body bypass, msd cap rotor and plug wires with ngk nitrous spark plugs, bbk shoty headers,3" catless exhaust, underdrive pulley, 160 stat, and slp fan switch, 700r4 trans with shift kit,3:73 gears and 17" with 285 40 17 tires. The previous owner said he had the car tuned for nitrous and my air fuel gauge which is a narrow always goes in the green which is rich when i get on it. The gauge goes like 3 clicks in the green so pretty far away from the middle of the stoich where i believe a N/A set up should be. Am i loosing power running rich and also i only get like 12-14 mpg average on a tank? I was thinking mail order tune madz28 or pcm for less. Which is better and will gain some horse power back along with a couple mpg?

I fixed my post i was in a hurry before now it is readable i need your help? Thx

dude that narrowband gauge is nothing but a light show, get a wideband setup like an LC1. You will get far better data that way.