You're probably talking about the input speed sensor and/or the output speed sensor (if your model has one). They are about $20-$30 a piece, it's a cheap fix.
The speed sensor is located on the drivers side of the transfercase, you will see a sensor with a connector, that is your sensor.
in the valve body which is inside the transmission.
There are 2...an input and output sensor, and they are located on the transmission housing, driver's side.
Pre 1998, it is on the back of the trans/transfer case After 1998, it is the rear axle abs sensor on top of the rear axle.
A 1998 Jeep Cherokee does not have a mass airflow sensor. It uses a manifold pressure sensor, MAP, which is on the rear of the intake manifold.
For a 2WD model, on the driver's side of the transmission housing look for two identical sensors at opposite ends of the transmission housing held to the body with 10mm bolts and captive washers. The plugs release by pressing down on the two-pronged tab.
Your speed sensor on a 94 jeep jy is near the crank shaft. I hope i answered your question.
It is something that does happen from time to time. Replace the o-rings on the sensor and the plastic adapter housing it sits in.
You take the Jeep to a certified mechanic!
"how do you change a throttle position sensor on a 1998 jeep grand Cherokee?" could someone without any experience do it?
If it is a 1997 or older it is in the tail housing of the trans. If it is a 1998 or newer the speedometer signal comes from the rear axle speed sensor on top of the rear axle.