Help identify sensors near timing belt

[BostonGST]

Previous owner told me he swapped engine with a JDM one, i didn't take too much of what he said but there definitely is a newer engine in my car. It runs great no real problems, hesitates a little to turn over but no driving issues. However, near the timing belt there are two of the same plugs (only one is plugged in) and an empty plug slot that's not used. I tried looking at that interactive engine diagram for dsms that's online but it doesn't show it, so i thought I'd post a picture and see what you guys think. From my research it looks like the CAS? That sound right?

Also I unplugged it to get better reach to change a vacuum line and accidentally plugged the other one back in. My car would try to turn over but nothing, I realized what i did, switched the plugs and it turned over fine. So one must not be connected to anything correct?

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[19Eclipse90]

2g Engine Bay Electrical Connections

One is for the crank sensor, the other for the A/C compressor. Neither is a normally open connector. If you don't have A/C then yes, that connector will go to nothing.