Pinpointing Thermistor Issue

I have been running a E3D lite6 for a while now. Lately it has been acting very strange during heatups when it gets to 180c (see graph). One second it will be at 180c, then 230c. I have ran PID autotune and have the correct thermistor in Marlin. I want to change the thermistor input in Marlin to make sure its not an issue with T0.
I believe it is in the "pins_RAMPS_13.h" section of the firmware, with the displayed section of code. How would I change Extruder 1's temprature sensor input from "T0" to "T2" in the firmware? Note:Running a EFB setup.
"

#define TEMP_0_PIN         13   // ANALOG NUMBERING
#define TEMP_1_PIN         15   // ANALOG NUMBERING
#define TEMP_2_PIN         -1   // ANALOG NUMBERING

Any other ideas are suggested. I would like to make sure its not a problem with my setup before attempting a service claim.

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Prusa i3 Rework - Ramps 1.4 - E3d Lite6 - Full Graphic LCD Controller

Just change

#define TEMP_0_PIN 13 // (written on pcb as T0) ANALOG NUMBERING
#define TEMP_1_PIN 15 // (written on pcb as T2) ANALOG NUMBERING

to

#define TEMP_0_PIN 15 // ANALOG NUMBERING
#define TEMP_1_PIN 13 // ANALOG NUMBERING


T1, pin 14 isn't mentioned as its the bed

Random fluctuation could also be that the Thermistor has gotten lose from the hot end.

Can also be cased by voltage issues (power supply to weak)

I would also remove your LCD if you have one for now, as they suck lots of power from the 5v rail, see if that make it more stable.

Power supply is a 30a 12v supply. Input there reads 12.13v. I removed lcd and got the same result. I have attached another graph with the Temps without lcd. It hopped from 205 to 225 twice and 208 to 216 once. What is strange is that I did a 5.5hr print yesterday and Temps looked fine. The problem seems to last only in the 1st few minutes of heat up (second graph).

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Prusa i3 Rework - Ramps 1.4 - E3d Lite6 - Full Graphic LCD Controller