Coolant temperature sensors on '82 4x4 base 5sp. pu, there is #1 and #2 sensor. they both look alike and set side by side next to thermostat housing, #1 sensor is closest to valve cover. need to find a used #2 but dont want to get stuck with wrong one when looking. Is there a way to tell them apart. there's a number on the nut portion of the sensor with 50B & 6B stamped, does this lable it as one or the other? Searched everywhere I could think of...
I plugged the sensor so as not to leak but has no function now, think not being connected is making truck run rich as noticed new carbon in tail pipe after 120mi drive?

Added ANSWER!!!; Just had a thought to check the connectors and see if there different, maybe they wont interchange? Removed the other sensor and connection was different, was a bitch getting off. The number 2 I need has a square shape plug with 2 noches on 2 sides of square, other one just a smaller square. Answered my own question, LOL

PS> FYI, Good news is found one on ebay used for 27 w ship, bad is i searched by part number on RockAuto and found it new for 40, thats ok. The other one #1 was 20 , good prices and both with correct connectors is what I wanted. So found searching by car model wont always show what is needed, also search by Model Number if possible to try and get correct aftermarket part.

(they're numbered in the service manual 1 & 2.
#2 ; Toyota pn. 89428-20050 (this is my bad sensor)
#1 ; Toyota pn. 89427-14040 Might be for temp gauge?