94 S-10 engine sensor..

I have a 1994 S-10 pickup with the 4.3 v/6 w/5 spd.trans.My temp gauge stoped working and the Service Engine light game on.I found a blue wire and a green wire laying down near the steering box each about 12" long.Does anyone know what the two sensors are that are on the drivers side between #2 & #3 spark plug are?