97 F150 automatic shifting problem

When in city driving, it feels like the transmission is shifting back and forth from a higher to a lower gear. I turn off the OD and it still happens. Highway is smooth. I get the impression a sensor is out of wack causing it to try to shift too much. Is there a sensor that controls the upshift or down shift? Is this an indication there is a bigger problem? I just bought this super nice, XLT with only 57K miles. Excellent condition. Other shifting from start is smooth. Any ideas?

There is a MLP (Manual Lever Positioning) sensor, als o called TR (Transmission Range) sensor bolted on the side of the transmission under the shifting linkage that tells the computer which gear you are in. Also the Throttle Position sensor will cause shifting concerns. Good luck.