2004 F150 5.4 3v Transmission

[backdraft3377]

I just got my Diablo U7151 today, put in and works good BUT when I get on it shifts real hard. Can you help. V.9r08

[mikel]

Can you post your calid?

What tune did you install?
Do you have a CAI?

[backdraft3377]

Thanks for getting back to me. I don't have the cable extension yet try to get one this weekend. I just put in the 82 octane performance. I did set the tire size, I'm runing LT315/70R17. I also put in a K&N air filter just filter. I also put in new plugs. The truck runs good. Normal driving it shifts good but out on the highway when i pass a car the down shifts is real hard. Looking at the manual on line it shows a SHIFT FIRMNESS but I can not find it in the settings. Would I have to adjust the SHIFT POINTS?

Thanks for your help