Fixed! Thanks to @
geraldjust he was able to confirm my suspicion that it was an electrical issue. The first time I hooked up the techstream to the car it had multiple codes from the ABS module. I took a picture of them and cleared them. When the issue occurred it only threw the one code, C1237.
The last time we hooked up a third part scanner as techstream was acting up like it always does. It showed two codes C1237 & C1241. The new one is saying the voltage is either too high or too low.
I wired the abs module directly to the battery and it threw the same codes. Talking to Gerald, he said he had the same code whenever the battery voltage drops and the 86/BRZ usually idle with the alternator producing between 13.8-14.4 volts.
The Tundra system which my swapped engine is from idles between 12.9-13.2 volts. I hooked up two diodes to the alternator regulator sensor and now it idles around 13.8 volts. Took it for a spin and finally no codes so far
