Exhaust Kitty Or No Kitty?

[Doughboy21kd]

I have an 05 Dodge auto... In process of bombing it... As far as the exhaust goes what should I do. I live here in WA in an area that i have emmissions..... I am going to stay with the stock 4" i am just wondering if i should Take CAT out and do straight through muffler or leave CAT in and straight pipe from CAT back. with 5" tip... . Just wanting to get some thoughts on what you guys have done and what you think i should do... . half the people I talk to say that Emmisions place probaly wont even notice that it missing... also have heard that you need to leave something in because people have said that the motor requires a little bit of back pressure... THANKS PLEASE HELP.

 

[NickSullivan]

Someone please speak up on this. I am in the process of doing the same exact bomb and could use some help soon. Thanks.



Sully.

 

[Hokey]

If you want it to be quiet-leave it on

If you want to bomb it up past 450hp take it off

If you remove it drone in cab can be a very noisy problem unless done correctly.

Everyone has a different opinions and I hope some will chip in. this is My humble opinion.

 

[nick05]

i have no muffler w/ the kitty on with 5" stacks. it's got a nice tone for me at least. like 'em loud and proud. not too bad on the drone. went on a 16 hour trip and my old man said afterwhile he got used to it. i'd say if you have to go though emissions leave the kat on its not going to make a world of difference. i don't need emmisons here in wis. but i still have the kat on. or i just might need to experiment and take off the kat. just straight it and be done with it.



nick

 

[Cummins Cowboy]

just take the exhaust apart and use a long piece of rebar, and rot out all the insides of the cat, next reinstall the cat, only its not really a cat anymore it just still looks like one

 

[NickSullivan]

Awsome thanks guys, one quick question though. Should I just put a glass pak without the cat on or straight pipe it without the cat too.

 

[TowPro]

I live here in WA in an area that i have emmissions.

Will the truck pass emissions without the guts of the cat? I bet they at least want to see the cat is still there, check the law first.

 

[nick05]

all depends on what sound your looking for. mellow tone with muffler/ loud when you get on it otherwise don't punch it if you don't want it loud straight piped.



nick

 

[MHorne]

i have a 2005 4 dr sb and i straight piped it all the way. drone is not too bad but i wouldn't gut the cat and put it back on. It was said earlier in a thread that gutting it and putting it back on does something to it but i don't remember. And supposibly some emmissions places won't pass you if you don't have the cat there visibly. But i think it all depends on the guy who does your inspection. If it were me i would straight pipe and like it was said before be done with it.

 

[Doughboy21kd]

Thanks guys If I leave the KITTY and put a muffler on it besides the stock muffler will it sound good when you get on it? and if so what muffler Is a good one to go with THANKS AGAIN IN ADVANCE.

 

[NickSullivan]

Ok, I found out a few things today. First the muffler needs to fit the existing piping, the stock muffler has its input side down low and its output on the high side of the can. So the replacement muffler needs to fit the existing plumbing if possible. Second the length of the stock muffler is pretty long, I think finding an aftermarket muffler to fit the stock mufflers plumbing might be difficult, thus the reason everyone is going with complete systems for 400 to 500$.



I also tried to take apart the exhaust today in my barn so I could get to my cat. I loosened up the clamp in front of the cat and the two behind the cat and I was unable to get things apart. After looking at it, it seems I may have to completely remove the tail pipe and muffler section to be able to remove the cat. Am I missing something, it just would not come apart?



My plan is to modify the cat and keep the stock muffler and see how it performs and sounds before investing into a complete exuast system.



Thanks again,

Nick

 

[DJennings]

The muffler is what is restricting most of the exhaust flow. You aren't going to get much out of gutting the cat. I replaced my stock muffler with an aeroturbine. When I pulled the stock muffler off, it was black inside with soot falling all over. After the fact, I was getting better mileage, lower egt's and a more responsive throttle. It sounds awesome and only has drone when I get on it.



The aeroturbine 4040L is half the length of the stock muffler. I installed that right next to the cat and then added the bent pipe to the tailpipe that came with the kit I bought. It took about an hour.



You can see the kit here: http://www.dieselpowerproducts.com/exhaust2

 

[NickSullivan]

Wow thanks for the info, that sounds awsome on the sound bite from the website you provided and its an economical solution. I also found out about MBRP having a replacement muffler. Anyone have any experience with this kit?

 

[jwduke]

I would leave the kitty, and install a free flowing muffler. I don't think the kitty has a lot of restriction to it.

 

[Mark Craig]

Doughboy21kd & Sullivan,



Check this out if you have a 2004. 5 + and plan to leave the Kitty this is THE way to go, for most folks that drop the kitty it is still THE way to go.



https://www.turbodieselregistry.com/forums/showthread.php?t=144237



Mark @ DPPI

 

[NickSullivan]

Mark,

Thanks for chimming in. After reading that it sounds pretty mellow of an exhaust system. I think what I want is a truck that sounds like it has a different exhaust system installed on it. Why would you choose the MBRP system as apposed to the aeroturbine?

Nick

 

[nick05]

i agree with djennings. the kat isn't the major restriction the muffler is. and for doughboy why would you want to put on a second muffler and possibly restrict it more. i'd just take the stock one off. there's a few sites that have sound clips you can listen too.



nick