I have an LLY and all I have done is Edge Juice and drop in K&N filter.


I would like to do an exhaust and air intake upgrade, but I have a few questions on the exhaust.


On the LLY motors I have noticed that most exhaust kits delete the catalytic converter. How is this going to affect emissions and inspections in the future? Here in Texas they have started sniffing already,just a matter of time before it comes to my city.


also, with the exhaust and intake kits are you seeing any mileage improvements? I am not complaining since my last HD was a 6.0L


thanks, great site

I did the 4" exhaust from the down pipe back and saw only about 1 MPG increse.

Most systems will bolt up from the 4 bolt flange back. Since the cat is located on the front pipe, it is not replaced. If you are looking at a system that includes the front pipe, just don't use it. Hope this helps.

thanks for the info and replies..





what about intake kits? any mileage improvements there?

briano,


Most every exhaust system has the front pipe (delete pipe) as a seperate item as the CA trucks have had cats long before the LLY engine etc. So to be "legal" you had to have a cat back system. The front pipe we sell will bolt into a stock truck, and or any of our systems your option etc. For air systems we ONLY sell the Pro Guard 7 intakes, they are the only high flow system that stops the dirt but still flows air. The Stage II system is our most popular. I can't quote exact MPG changes but we get calls from folks all the time that get 1-2+ MPG with an exhaust and air system. Call us if you have any questions etc.


MBRP EXHAUST (http://dieselplace.com/forum/forum_posts.asp?TID=11123&PN=1)


Mark @ DPPIEdited by: Mark Craig

Mark, I looked at your site and listened/watched the video clips of the exhaust. It sounds like the duals are quieter than the singles? is that true?


I would probably still want to keep the cat on mine for emissions testing and all.

briano,


Well sort of but not really. They sound quieter because you aren't hearing the full level of both pipe exits in a video/sound clip like you would if you were standing there etc. The overall volume is basicallythe same.


Mark @ DPPI