I gave a rather extended list of tuning options ordered by importance to fix the OP's issue.
Just note that Zero Expo is best even if Steering Speed is not available, then I listed lower priority items to help solve the problem where I don't feel it's necessary to invest in a quality radio...
I just want to emphasize how horrible expo is for steering, yes it reduces sensitivity when tracking straight and can actually be useful for doing speed runs where you want very little steering input to make small corrections when tracking straight, but this feature comes at a cost... as the...
There are a lot of tuning options available to reduce the sensitivity and here are some ways to address it by priority, only make 1 change at a time until you get the truck to handle to your liking:
1) If you have a computer radio, then reduce the "Steering Speed" setting if your radio offers...