Looking at this same problem on a few units myself. I have checked the injector for bad orings, leaks at all of the intake system to no avail. I have also preformed the idle air relearn and the code keeps coming back. These are on new trucks with less than a thousand hours. Manufacture has stated this is a reoccurring problem and will likely come back. 10 trucks at the same customer 4 showing the codes since new.