shifting weird after new tire install

[Turbo6]

oem was 265/70/r16

I installed 265/75/r16 and now i am getting a little slip at low speed part throttle on the 1-2 and 2-3

I disconnected the battery to reset the ecu and the problem goes away for a few days then comes back.

Is there a way to reprogram the ecu on a 2004? Are the tires the problem or is it something else and its just a coincidence?

 

[Muadeeb]

Sounds more like a transmission issue. Going from 1 -> 2 the band is applied, and 2 -> 3 it is kinda removed and a 2nd clutch is applied. As in there's pressure applied to two sides lending it to not effect anything.

 

[Just a Hunter]

I would be doing a drain/fill of my trans asap and see if it makes any difference.

Valvoline Max Life ATF would be suitable for this check.
Allow time for the new atf to circulate and mix with what's still in the transmission.
If it improves, drive it a few miles and then perform another drain/fill.
If it dont improve, find a good transmission shop.