Got a 1991 Camaro RS, 305 TBI

Just pulled the motor yesterday (puked all its oil and threw a rod), noticed a strange plug on the wiring harness that was disconnected and can't figure out where it went.

It comes out of the harness by the knock sensor and the starter motor, and has a plug identical to the knock sensor plug. There was a broken off piece of male plug in it, it was blue.

I can't find anywhere on the engine where it goes, it was laying to the side.

What is this?

Also, any tips for replacing a broken passenger side engine mount? The nuts seem impossible to get to.

And I've just got to vent on how much of a PITA it was to separate the engine and tranny when the engine is locked up, can't get to the torque converter bolts. Had to remove all accessories, water pump, radiator, and condenser to make enough room to slide the engine forward off of the transmission input shaft, and I'm really lucky it didn't damage it.

Also almost flattened myself under the car, slipped off the jack, big *** Delco jackstands saved my life

 

Coolant sensor plug in the right (pass) head. Same connector as the knock sensor.

There's no easy way to get the motor mount off. You have to go throught the hole in the K-member. Swivels help.