That green connector is for your ground for Mixture Control Solenoid dwell. It's not supposed to be connected to anything but don't let it touch ground, either. During diagnostics, you hook up a dwell meter and set it on 6 cyl scale, and you can check to see if the O2 sensor (as long as the car is in closed loop) is doing its job cycling the mixture control solenoid. lean or rich. It's a tune-up thing.
If it's original equipment uner the hood, it's a late-year 86, or 87 442. You can tell by the 622 A/C compressor. Sometime in 1986, the 198 compressor got updated to a 622.
That quonset hut vacuum tank over there by the HVAC housing is used because the car came without cruise control. Otherwise, the vacuum ball would be located on the driver fenderwell just outboard the master cylinder. I will go out on a limb and say MOST of the 442s of that era got the K34 cruise control option added. And the reason for that is two-fold....first, the select-a-unit thing that most dealers used for ordering lot cars was G1-G4. The only select-a-unit that DIDN'T include K34 was G1. Secondly, people and the dealers would try to add the equipment needed to kick in the WL7 popular option value package which included credit for [IIRC] K34,N33 (tilt),U75 (pwr antenna) & UM6 (AM/FM stereo radio with cassette). Saved you 475.00 on an 86 or 87. 442s weren't cheap! Interestingly, G80 limited slip was NEVER included in any package for VIN 9 Oldsmobile and would always be an a la cart option. Strange. You would think all VIN 9 cars would come with G80, but, oh well.
A note about the WL7. It was NOT always on the window sticker and the RPO was an administrative RPO only, it included no physical equpiment. It was a credit that was received if the dealer included WL7 on the ordering sheet. If you bought all the options that triggered the WL7 discount, the dealer had to add WL7 to the order sheet in order to get the discount. If he messed up and didn't add WL7, you still got all the options, but you didn't get the credit.
