Aaron P.

Any engine codes? Also do you have access to a good scanner? One you can watch data stream and perform fuel trim reset.

There is your issue..you should have battery voltage..apply voltage with jumper wire from battery…bet it clears up if plugs aren’t fouled. I know the 2013 that I am working on fuse 18 feeds upstream O2 sensors and feeds another fuse in which is for downstream O2

Also want to add I read the voltage at O2 sensor. Reading was battery volyage but somehow was being messed with just enough to effect b1 s1 O2 sensor

Well figured out what was causing my issues.(2013 2500Hd 6.0) The truck I am working on is a state hwy truck. This being said it has an auger or spreader on the rear for salt. The feed wire that powers the control unit was tied into (Underhood Panel) fuse #18 which feeds (B1S1 & B2S1 / B+ Ignition Supply) Removed wire now runs perfect on both banks. Where before Bank 1(Cyl#1,3,5,7) was missfiring. Casey I know you probably dont have a wire tapped into your O2 circuit but you may try pulling fuse #18 then apply B+ to the pink wire @ the O2 plug. There is a possibility you have a faulty fuse panel. Hope this helps..

Im just getting started on this one. All I have done so far is swap B1 S1 & B2 S1 O2 sensors to see if issue moved to other side. In which it did not. Same as you B1 is rich with missfire cyl 1,3,5&7. Also has recently had converters removed. Have you tried an injector balance test?

Did you ever resolve the issue I have a 2013 2500 6.0 doing the exact same thing