Ok I just bought a second Xterra, a 2005 S 4.0 2wd. My question is when driving I have to keep the OD off or she will keep downshifting and upshifting. Plus tach reads higher than when I turn OD off. I’m getting better gas mileage with it off. Is this normal in the second gens or what? Previous owner stated it had been checked out by multiple transmission mechanics and can find nothing wrong/or a reason for it doing this.