The CPS doesn't make the list yet. The issue is a no start after the head gaskets were replaced. If the truck was running before and now after the HG's were changed it won't start then I wouldn't look any further than the HPO system which includes the injectors. Did he plug the wire harness together above the drivers side VC? Is the WTS light on? Does the tach move when he cranks. These are the areas that you can check on the spot.