According to the dealer the injectors tested fine for flow, not sure how they checked them but that is what they say. It seem that just after I hit 100,000 miles the thing just gave up. As for the exhaust I'll check that today and see what I can find. I should add that it's also been changed to a 3" exhaust with a high flow cat and a flow master 3" single in dual 2.5" out. Also this has been in the truck for over a year now. Thanks for all the help guys and I'll post more I as I find out.