p0120, stalls, and ecu resets

[Carnesaur]

short and sweet version
>>own car for about 2 months
>> car is fine no problems
>> suddenly! random days apart stalls
>> after one stall, get DTC
>>p0120 Throttle Position Sensor
>> also notice this on obd2 test

What the hell is possessing this car?
I've read up and people say TPS isn't the prob. My mechanic says TPS can shut off the car.
He tested the Alternator and battery and says they're fine
But why would the TPS reset the ECU and board data?
Check the pic, everything used to be green. This now looks like a loss of power or just ecu reset.

It also seems like there just isn't enough to power the car. The dash dims if i have the car idle, and i press the brake, turn a blinker on, turn on the ac. I wonder if when I am driving hard, its asking the car for power than isn't there. What should I do? New Battery? Alternator? ECU? TPS?

 

[DogWhistle]

A sensor is only as good as its wiring. THere are tests to verify whether the TPS is bad or not. This is an easy to use guide: http://www.oocities.org/motorcity/downs/7678/dsmtests.html

Trace the wiring ALL the way to the ecu to make sure it isn't damaged. If that looks good, what have you got to lose by replacing the TPS?