I am hoping someone can help me. On the passenger side, side of engine towards the back just below the exhaust manifold, is some kind of sending unit with two electrical prongs. Any idea what this is? I can’t find it anywhere.
Thanks!

What year car are you talking about. On my 72 it is a switch for the emissions. It had 2 green wires if I recall right. It is located in the cylinder head and is a temp sensor. Not for the gauge but to tell the Emissions that the motor is up to temperature. Very crude system by todays standards and most have been put in the garbage can.

Sorry about that, it is an 81. My thought was emissions too, as I know the temperature sensor is on the other side in front. It is broken (Metal prong broken off) and I am wondering if it is worth replacing.