P0137/P0138 o2 sensor circuit low 

2018 GMC Savanna 3500 6.0L
DTCs: P0137, P0138, P2096, and P2271
Code Descriptions: 02 sensor Circuit high voltage Bank 1 sensor 2, o2 sensor circuit low voltage bank 1 sensor 2, post catalyst fuel trim System too lean bank 1, and o2 sensor signal stuck rich bank 1 sensor 2.
Tools Needed:
Crescent Wrench or 7/8 Wrench (preferred)
Penetrant spray
Dykes or Wire Cutters
Anti-seize Lubricant
After replacement if codes still remain chances system needs to be re-learned by test driving a few miles and then again resetting permanent stored codes.
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