Curious electrical 1-wire connector on left exhaust manifold flange at crossover

[Ed81DMC]

Repair question - I’m removing my exhaust crossover and one of the left bolts attaching it to the exhaust manifold seems to have (by feel, I can’t see it) an electrical connector attached to it. My manual doesn’t even show an exhaust system diagram, let alone an electrical connector in that area. Anyone please tell me what it is? I gently pulled it and a black plastic single wire connector came undone. I can’t feel the connector it came off of but I’m guesing an exhaust sensor of some type. It points upward and slightly toward the engine block. It is NOT the oxygen sensor, which I can see below it pointing to the left side of the car.

Sorry, is there a better forum to post questions - I didn’t see it.

By the way, what is the best sequence for unbolting the crossover pipe, cat and both exhaust manifolds? I’ve already got the muffler out. I can’t easily access the flange nuts for the left manifold. They’re too closely wedged between the crossover pipe and engine block to fit a socket extension in. All the crossover pipe to converter and manifold nuts face forward. Can only access the outboard nuts.