Duramax Seventh Generation: 2020+ (L5P)
I have a 2020 GMC 1 ton Denali with around 27K on it.
While pulling my RV to Florida, I got a check engine light. I pulled into a car parts store and they read the code. It was on cylinder #5 and it said the cylinder was excessively retarded.
I cleared the code. No more codes the rest of...