Chrysler Repair: tps issues, throttle position sensor, o2 sensors

Question
QUESTION: I have a 2002 Dodge Dakota, 3.9 liter. Received p0123 code and began to troubleshoot. Voltage readings from center pin of wire harness to both outside pins are 5.1 volts and 4.7 volts. Should I have 0 volts on one side of the connector when throttle position is at idle? Seems to me that it represents wide open throttle. I suspect a short in the harness. My question is as follows; where does the voltage feeding the tps originate? How can I confirm a short? Please be as specific as possible, as I have no wiring diagrams to reference. Thank you for this great website.

ANSWER: POSSIBLE CAUSES
THROTTLE POSITION SENSOR SWEEP
INTERMITTENT CONDITION
THROTTLE POSITION SENSOR SIGNAL CIRCUIT SHORTED TO 5 VOLT SUPPLY CIRCUIT
THROTTLE POSITION SENSOR SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE
THROTTLE POSITION SENSOR INTERNAL FAILURE
SENSOR GROUND CIRCUIT OPEN
THROTTLE POSITION SENSOR SIGNAL CIRCUIT OPEN
PCM


U will have 2 5 volt signal wires  one is on the
orange wire 5 volt
orange and blue 5 volt
and the ground wire will have 60 ohms of resistance with key on
chk all this with key on and tps unpluged
let me know what u find out

---------- FOLLOW-UP ----------

QUESTION: Voltage @ orange wire 5.1 volts
voltage @ org/blue 4.7
60 ohms at ground wire.
The truck runs well in city, however, at highway speed power loss is dramatic! Almost like it's running out of gas. Also, popping or backfiring is present. I investigated further today and found the o2 sensor before the cat converter was directly shorted to chassis. Two of the four wires were shorted. I replaced the sensor and so far, all is well. Would this condition cause the loss of power and very low gas mileage? Drove it only a bit today, so condition still may be present. Also o2 sensor was very black and sooty. Thanks again!!

Answer
the upstream o2 sensors are one of the main things the PCM looks at the adj the fuel to air mixture  so yes  if one is bad or giving bad info  it will throw all all kinda stuff as u have described   U should also have had more then just a TPS code  more like an o2 code as well.