I had to replace the entire fuel rail system on my duramax also. If I understood correctly GM had some aluminum injector parts that do not hold up. Mine blew apart with only 2000 miles left on the 100,000 mile warranty, so I was lucky. GM knows the parts are defective because the replacement parts are steel, not aluminum. Should be a recall on all of the affected models, but I doubt it will ever happen because it cost 8-9K to fix. My mechanic had done 5 others when I came in, he hasn't had any problems with any he has fixed. I have put 45,000 miles on mine since then and haven't had any problems.