Q: Where does this plug go? Please help.

[RubyRed240]

Hey all, I was wondering if anyone has any idea where this red plug goes. Whatever it is, when it's plugged in it gives me an issue where my vehicle basically goes into limp mode (rev limiting) and I have slow acceleration on the first attempt to push the gas pedal. Once I unplug it, the vehicle resumes normal operation; obviously, the car can run without it but I'd still like to know.
I'm fairly sure it's a sensor but I'd like to know which one. Anyone have any idea? Thanks all.

The plug is near the TPS and the air intake on the front passenger side of the engine.

[biggie]

Hard to exactly tell from my phone but it looks like the two wire Temperature sensor going to ECU. Replace the sensor shouldn't be more than $20-$30.

[s14280zx]

Looks like the contacts need cleaned, too.

[RubyRed240]

Thanks for the help guys, I appreciate it.