Haven't posted an update in some time. There was still a bit of troubleshooting I had to do on certain other things that wasn't posted here. I was never able to get rid of all the DTCs in time before registration expired, so it's been in the driveway, since. I think I am stuck at the 5th or 6th revision (no PI tuning yet, still disconnected). NYPD was working with some other state police departments to run a sting on any cars with plate covers, ghost plates, expired insurance/registration, etc so I just didn't want to take any chances after seeing all the reels and videos of dudes getting arrested because of it.
The knock sensor issue turned out to be that the knock sensor was just plugged into the only other identical connector under the hood that was incorrect. It has since been fixed.
As of last night, I removed the V2 relay that was sent by Greg Sange to try and fix the issues with the V1 that I had. I was able to get down to just 1 code with it, P2010 (IM runner control circuit high) but it still pulled a code. It might have to do with the grommet on one of the 2 wires being too thick, that wire didn't want to seat in the connector nicely. I may try to replace that grommet with the next size down since I have some lying around, but the OEM black box and solenoid/plunger was plugged back in last night. At first, was still getting a code, but then I remembered reading somewhere that the plunger needs to be ziptied down. That seemed to help. I idled for 35 minutes last night, and for the first time since owning this car, did not get a code at the end of the idle session, and not a pending code, either. Going to try starting and idling again tonight to see if the results are the same. If they are, I may finally be able to register and inspect this thing!