O2 Sensor Help

[08Silverado4.8l]

Hi everyone, not quite a tuning question but I'm having an issue with my O2 sensor B2S2. It throws multiple codes but ultimately it says it's both stuck lean and rich and heater issue.

Its a 2008 silverado 1500 with the 4.8l. I replaced the exhaust manifolds with shorty headers and the catalytic converter Y-pipe with Flowmaster High flow cats in march. I had to replaced the heads with PRCs I bought from texas speed and a stage 2 cam I would like to put in but want to get the O2 sensor figured out first so I can use the close loop tuning and pass emissions (which I think i can do with the stage 2). I did find a small leak at the bottom of the CAT and plugged that hole before replacing that O2 sensor a couple days ago. But I continue to get the same codes and non-sense.

Looking at the scanner and the mv readings, both B1S1 and B2S1 have look really clean and similar to other scans I've seen from other trucks. the O2 mv graph on the other hand has a ton of artifact. I've looked around the CATs for more leaks and have attempted to look at the wiring but that has proven difficult to say the least.

A couple things, is there a direct way to determine if there is a bad wire and how do I trace it? Is it worth just replacing the wiring harness (the wiring definitely looks a little beat up)? Or am I completely off track on my thinking that the wiring is the issue? I can't see it being that the cat went bad already and I can't find anymore leaks. So I'm only assuming a bad wire because I also occasionally get a RF Speed Sensor fail.

Mike_08Silverado_O2_sensor.png

Sorry for the long post but I hope that all makes sense and some of you might have some good insight.

Mike

[08Silverado4.8l]

Also, I have looked at the wiring diagrams, but jesus, I am not any where close to understanding electrical engineering. I know what wires to look for now but to trace the whole thing...

[5FDP]

Have you moved the rear o2 sensor to the other side to see if the issue follows?

Closed loop can still work without rear o2 sensors just for an information standpoint. Having a check engine light however would fail an inspection or if a readniness test would be incomplete.

[GHuggins]

You can kill all of the rear O2 codes and pass the test even without cats... Another thing to keep in mind is that cats have to go through "regens" or burn offs just like diesel dpf's - this was per an engineer and verified. If you have cheap made cats or have fuel getting to them from a cam then it's possible is just bad. Sensor doesn't look bad in the log... You can always do as mentioned and switch banks with wiring or whatever to see if codes change to the then corresponding bank. Another thing to remember is it will use precat O2's for logic testing - if it's got an issue - may cause your codes for the rear...