Can u use the u7146 to check your airfuel ratio?

Sorry I didnt tell you I have an 03 gt

I am so very confused! The only options I have with the tuner are Factory HP tune and Diablo tune. So you are telling me I can only change the gear and tire size under the diablo tune? I dont have any custom tunes. I could sure use one though! I have a coldair intake,75mm tb,c&l plenum, off road ...

Yes Iam using the Factory HP tune, just through the winter. Yes I have to drive it. I put in the 4.09 setting but It does not fix my speedo!! It reads about 15 mph over. Just for the heck of it I tried putting in 4.30 4.56 and so on, but the speedo remains the same. Its like the tuner doesnt work ...

u7146? I have this tuner and I cant figure out why I cant set the speedo for a 4:10 gear. Its like the tuner does not work. HELP! I can only set it for 4:09. So I do and the speedo is way off. no matter what I set the gear to the speedo reads the same?