What is causing my car to rev and go nowhere when in gear.

TPS SENSOR.
IT CONTROLS SHIFTING AT THE RIGHT TIME
AND COULD ALSO CAUSE ALL OF THE SYNMTHOMS
THAT YOU HAVE LISTED SOMETIMES WITH OUT GIVING YOU A CODE GOOD LUCK

I would start by testing the vehicles main Earth cables under the bonnet. Could be high resistance caused by failing cable. Jon

your computer is f*cked

sounds like the synchros are worn out. you need a trans

Go to www.hmaservice.com and register( Vehicle by VIN). Afterward, you have access to shop manuals, service bulletins, wiring diagrams, etc. about your vehicle.

The output speed sensor is located on top of the transmission output shaft, this will send speed value to the transmission control module (TCM).
The vehicle speed sensor is installed on the differential of the transmission, and sends speed value to speed gauge on instrument cluster.

Check also IAC valve and look for vacuum leaks using an hand tool gauge(Vacuum Gauge and Fuel Pump Pressure).

The turbine shaft speed sensor can cause this problem, It is also know as the transmission input shaft speed sensor. It will cause the transmission to **** and also stick in 3rd gear, which wound cause slow acceleration.

I have a 2002 Hyundai Sonata and I had the same problem. But mine would always shift into 3rd gear and STAY there until I turned the car off. I took it to a Hyundai dealer and he had to rewire a speed sensor on top of the transmission. Apparently a little animal got up in that tight little spot and gnawed on my sensor wires. The car has run fine since. To make a long story short, it might be your speed sensor on your transmission.

Hi,your car may have a bad tranny mount,if not souds like bad gear , (internal)

P1723 A/t control relay - Stuck on.
This Code is showing that the main control relay of the transmission is stuck on. When that happens transmission goes in to the fail safe mode which is being stuck in 3rd gear to prevent damage to the transmission