The last 3 years I've been driving my 07 jku with a CEL. I replaced cat conv, EGR, 02 sensors and nothing. Always there, sometimes the codes change. I came to the conclusion it was the pcm but never replaced.
Well Tomorrow I'm doing a big 3 wire upgrade w/ 1 ga wire, new terminals , and a new battery. After doing a lot of research I discovered what G104 is , the ground for all O2 sensors. Located on passenger side on bell housing behind a heat shield. After reading this today and realizing what it is , I remembered last year trying to clean that same g104 ground up and it looked worn, so I'm thinking that might be the issue.
If that's the case how do I replace that ground being it leads to a bunch of wires in all O2 connectors.