What is the difference between the 4040 and the 4040xl? At what point should I install it before continueing with the exhaust. All I see on my 04 is pipe from the turbo to the big 55 gallon drum close to the rear axel.

 

4040xl has a resonator in it. I believe that they want the aero installed as close to the turbo as possible. I'm not sure because for $20 I got myself a chunk of pipe.

 

Read all about them.
http://www.aeroexhaust.com/products.html

 

Actually, Aero reccomends installing in the same place as your existing muffler. Steve kinda thought that by installing it closer to the turbo you gained a little umph, however by installing it there ( up by the turbo ), you MAY wind up with the cab drone noise.

I installed mine ( resonated version ) back where the stock muffler was, lost the stock resonator,and I love it !!

 

Thanks for the info. I'm still learning about diesels. Crawled under my 04 last night and there ain't nothing on it from the turbo back to the 55 gallon drum? close to the axel. I guese if the drone is too loud I can add the muffler later.