Can someone please help, I don't know what to do. I had 2007 Jeep wrangler jk that had a check engine light that would not go off. Was saying all my o2 sensors were bad a p0420 and and bunch of others. all new parts didnt fix it, new Mopar OEM parts didnt fix it. took i to multiple shops and dealerships spent thousands in diagnostics with them telling me itll be $3000+ for new wiring harness. long story short I found a video that showed weird codes like mine where it threw a ton of codes. In the video they re wired the G104 ground and that fixed it. all but one code. So I had enough and decided to sell it. bought a 2012 Jeep wrangler jk this past saturday and now this jeep is doing the exact samething! this cant be real. when I test drove it had no codes and no pending codes. not its immediately throwing codes even after clearing them. point of note I took the same radio head unit and put it in this Jeep. Could that be what causes everything? both jeeps seemed fine until i did that. I uninstalled the radio and its still showing all the codes I left the negative off last night all night and codes immediately back on as soon as I plugged the negative back on. I also have a cheao obd2 that I use to read the codes and show info to the radio. I dont know what to do this literally has me in tears. anyone know where the g104 equivilent is on a 2012 Jeep Wrangler Please help anyone help i dont have any money left and cant afford to go through all I did with the last jeep. Thank you ao truly so much for your time and effort.

 

check the C300 connector. its behind the passenger side headlamp. its a large connector with a lot of signals passing through it. I also found my wiring harness was starting to get cut into near the steering column shaft knuckle is. This was brought to my attention from someone else on this forum.

 

check out the 3 pcm failure log

 

not really sure how to do that 😬 I'll also check the connector behind d the headlight tomorrow. Truly thank you so much.

 

If you remove the wheel liner its right there if your going to look at theC300
here is the grounds for the sensors

 

omg yes all the codes are all on that same ground location! That might be it!

 

you are the best! That was it!!! All 21 codes are gone! No check engine light!! I'm so happy thank you God! Anyone else out there if you have error codes for all o2 sensors check your grounds! 07 tp 11 it's the g104 ground location. 2012+ is the g102 ground location

 

Great!!! Glad I could help!!