2004 Chevrolet Silverado 2500HD , 6.0 Vin U Misfire

Vehicle came in the shop, with the SES light on and an obvious misfire. Previous shops had replaced plugs and wires, removed cats, replaced both bank 2 oxygen sensors, the ECM and had swapped positions of coils and injectors for cylinder #6. I scanned vehicle and found a misfire present on #6 cylinder on a regular basis. Performed fuel trim reset and vehicle ran better but misfire soon returned. Short term fuel trim was at -17 and long term was -30. Injector pulse with was 1.2 ms shorter on bank 2 than on bank 1, bank 2 sensor 2 was staying at about .038 volts and bank 2 sensor 1 would stay fairly high and occasionally spike to 1.0+ volts.
I disconnected b2s2 connection thinking it was shorted and would improve the misfire by setting a default value in the ECM. It helped but b2s1 was still spiking high. Plugged b2s2 back up and disconnected b2s1. Default voltage of .45 set for b2s1 and b2s2 started working properly and misfire was much improved. Suspected that b2s1 sensor was faulty even though it was new. I was looking closely at the plugs between b1s1 and b2s1 to see if I could remove both and swap sides to see if problem would follow the suspected faulty oxygen sensor when I spotted the problem. The tan wire was broken at the chassis harness connector for the b2s1 oxygen sensor. Mitchell On Demand listed it as HO2S low signal, I believe it is actually a return ground signal. Repaired wire, cleared codes and test drove. Problem fixed!!!!!!!!!!!!!!!!

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