Helping a friend diagnose his Duramax. Approx 180k miles, he bought the truck at 110 and the PO stated that he had replaced all the injectors recently. Highway driving, not towing, engine started running rough and CEL illuminated and speed dropped below 30.
Codes P-0201, 0204, 0206, 0207, 0700, and 2146 all came up.
I have read some of the threads on here about limp mode but they all seem to relate specifically to the ‘01 LB7. I also reached out to John Kennedy for some advice, but any thoughts here?