I noticed this wire has been hanging and my 89 240sx is in limp mode and i unplug sensors and the car sounds better

and now when i switch my ignition on the off position the car is still running even with the key out and with the battery unplugged the only way i get it to shut off is if I take out the efi relay. I have no clue on what's going on.
https://imgur.com/a/HTI6Afj
Update: i replaced the chassis and engine harness from a manual and ecu now the car runs and revs pass 2,500 rpms now