Hyundai Repair: speed sensor, tone wheel, couple cars

Question
I have a 1999 sonata.  The check enging light keeps coming on and the scanner says speed sensor. p0500.   Now, I have replaced the input and output sensors but the light still comes on after a day of driving.  Any other sensors I am missing?  Thanks.

Answer
P0500 refers to the sensor which reports vehicle speed to the engine/transmission computers.  

On the 4 cylinder, this is the sensor on top of the differential housing of the transmission.  I've seen several of these go bad.  

On the 6 cylinder, it'll be the right front wheel speed sensor.  Check the tone wheel on the axle shaft to be sure it's not broken or damaged.  Also check the wiring.  I've seen a couple cars with the wiring broken or eaten through by rodent.  I don't recall seeing one of these sensors actually fail, but it's possible.