Okay so I have a 1G DSM that had a check engine light code of 31 knock sensor went replace the knock sensor the knock sensor was definitely bad it had the black goo coming out after I replaced it I unplug the negative side of the battery for a few minutes to clear the code after I clear the code I restarted the car and after about 2 to 3 minutes to check engine light came back on I then hooked up my voltmeter and realize it was still code 31 so I unplugged it check the harness for voltage i had 8.6 volts coming from the harness plug after looking around the car and I noticed that one of the black wires on my O2 sensor was rotten and not hooked up could this cause my issue