Banks offers a down pipe for the 2003 6L PSD with a resonator to help reduce turbo screeching. I put a 4 inch turbo back system on my 04. I love the extra power and the throaty sound but i am not too crazy about listening to the turbo spooling up. Will the 03 down pipe fit on my 04? Will it make that much of a difference? Why did ford put a resonator on the stock 03 down pipe and not the 04?

I see no reason why it would not fit. Call Banks and have a chat about it. Better than finding out later.

Thanks for your input Max. I did talk with the Banks tech support. They were like you "I don't see any reason not" but they did not say 100% sure. Before I dropped another 300 bucks into this system I was hoping to hear from someone that has seen/heard one of these resonators to get an idea of how much of the the turbo whistle was eliminated.