My obd device said that my shifter solenoid a b and c are bad also my o2 sensors but I had the transmission rebuilt a year and a half ago also all o2 sensors were replaced about a year ago so I wouldn't think all that should go bad so soon so what could cause all that to act up and how to fix

 

There are no " bad part" codes, computer can only "see" if voltage or "connection" is out of normal range or missing.

So post the exact codes you are getting and the "meanings" you got for those codes


Solenoids in automatics get 12volts when key is on, the computer will "see" that voltage as it passes thru the solenoid on the Ground wire the computer uses to activate each solenoid.
So if there is no voltage with Key on the computer will set a code that it can't "see" those solenoids, not that they are bad, could be broken or disconnected wire.

In 1999 Rangers that 12volts comes from Fuse #13 in engine fuse box
And that same fuse is also used to power the O2 sensor heaters

So if you had transmission solenoid codes AND O2 heater codes then I would check that fuse

That fuse can blow because O2 sensor wire gets shorted by getting too hot being near exhaust pipe
So if fuse is blown inspect each O2 sensor's wires for damage
Each O2 sensor has 4 wires, 12v and ground for heater, and 2 wires that go to the computer