95 tracker transmission slip and poor milage

My 95 2wd automatic will miss 2nd gear and disengage when it's cold. Also mileage is poor - 23 mpg. Maybe it's the tranny? How can I increase mileage? Change differential ratio? This car should get more like 33 mpg. Revs high on the freeway.

my 95 did the same thing , i had to have the trans rebuit

Thank you. Do you think a 97 4-spd automatic frm the 1.8 liter will fit on a 1.6 liter?

not sure if the bolt pattern is the same , even if it does bolt up , i think you going to have problems with the computer