I recently put taller tires on my truck which has really robbed horse power. Some one told me you can change the ratio in the auto tranny thru the computor.Sounds a little far feched to me, have any of you guys dealt with this issue?

 

What kinda truck year, model, 4x4? wat size tire... wat mods are done to it?

 

Yes you can and need to have your tire size changed in the ECM. It will correct your speedometer that is now off a bit and will correct the shift points in the tranny.
However, correcting the ECM will not give your HP back. You will need to get a programmer to add a little HP to get fuel milage and HP back. Basicly what you did by putting taller tires on it was , you basicly gave it higher gear ratio's.
I have 35"s on my truck and noticed the same performance drop and loss in fuel milage. I bought the "Smarty" programmer and corrected the tires size and added a little horse power, now it's better than it was before

Go to your dealer and they can program the correct tire size for you.

 

You can correct the speedo with a Hypertech programmer too. You could probably justify buying the programmer with what the dealer is going to charge you.