Hyundai Repair: 2000 Sonata Transmission 2.4L, throttle position sensor, sensor tps

Question
The transmission would not shift out of 1st gear so the mechanic replaced the Throttle Position Sensor (TPS) with a used sensor because all of the local dealers were out of stock.  The transmission will now shift through the gears, but it shifts at around 4000 RPM which is much higher than normal.  Do you think installing a new TPS would get the car back to normal operation?

Answer
It's possible.  A TPS isn't normally one of the things I'd recommend considering purchasing used.  Being unused and out in the elements isn't good for the sensor.  One of the problems is that the contacts get dirty.  Driving the car helps keep the contacts clean as you operate the throttle.  I'm surprised the shop wasn't willing to wait the two days or so it would take to procure a new sensor.

There are three basic possibilities:
1.  The throttle position sensor wasn't properly adjusted.
2.  The used throttle position sensor is defective.
3.  You have some other issue causing your transmission problems.