The problem I am having is that at WOT my car doesn't want to shift gears and hits the rev limiter. This happens at the 1-2 shift and also at the 2-3 shift. I have had my car for 1 year and 3 months and I know that at one point i was not having this problem, I just can't remember exactly when it happened. The thing is that at any other % throttle it shifts fine and doesn't slip at all. It especially got worse when I had my 3.73 gears installed. I need to know whether this can be fixed through adjusting the shift points or whether there is internal transmission damage. I have TunerCat but I am new to it and don't know how to adjust the shift points. Any help is very much appreciated.

 

I had the exact same problem. Turned out the transmission needed rebuilt. Cost me $1500