[kbailey]

I'm not sure here but doesn't the Duramax monitor EGTs and then defuel accordingly? I could easily be wrong because I have an old 12 valve Cummins, but if it is the case you might look into a turbo back exhaust. That should drop your EGTs at least 200 degrees and help with the defueling. A turbo back system will also free up some horsepower and your turbo should spool faster. You might want to look into an exhaust system anyway if you are adding more fuel with a programmer. I personally like Silverline exhaust systems because they are all stainless and sound really good, but there are a lot of really good exhaust systems out there.