I had an 01 LB7 previous to my LLY that I have now and I did recieve a service recall for the injectors from GM. The recall basically said that if you did have problems with the injectors that they would refund you for the cost of the repair done at the dealership. My truck did have a slight surge at idle that would roll off and on, which I think was a sign of a bad injector but who knows. I put 80000 miles on that truck before I got the one I have know and never had any problems.