Have a 96 Dodge Neon, sometime the speedometer will work, sometimes it don't. Is there a fuse or something for it?

I think this has a speed sensor on the trans that controls the speedometer.

My "Check Engine Soon" light will come on for a day or two, then go off. Had it checked when the light was on and it showed two codes.
PO401 - EGR System Failure To Affect F/A
PO743 - TCC Solenold Circuit Open Or Short
Well, today the "Service Engine Soon" light went off. Even with the light off, the speedometer will work, then it won't. Also today, you can hold the gas pedel down to the floor and the car will not go over 45 mph. Would this have anything to do with the TCC or speed sensor?

I replaced the speed sensor and it does the same thing. The speedometer will work for awhile then it won't. Anything else I should check? Also my Service Engine Soon light will come on, then that will go back off too.

The two codes are running off a related circuit and the TCC would greatly affect your speed and the pcm information sensors, the TCC is located inside the trans pan, I don't have a diagram for the exact location.