2019 Silverado HD 2500 LTZ ZR1 Metallic Black 6.6 Duramax. 2003 Silverado HD 6.0 Gasser. 2003 Monte
I seem to remember that there’s a thread on here someone started not long ago about relocating the def tank to a place under the truck that doesn’t hang down so low. I’m really not the person who can help you with codes, I normally look up the codes on google, using the truck year and motor and GMC or Chevrolet.