childitch

I resentlly installed a 41" donaldson on my 04.5, I am hearing a rummbling noise at idle in gear, not sure what is causing this... Anyone have any input on straight pipping with regaurds to noise level,

PourinDiesel

Keep your muffler.
Straight pipe on my 04.5 sounded junky.

Bubba_CTD

I straight pipped mine and the difference between it and the stock setup is so much better now. It gives it a nice tone IMO... but I like my rides to be loud.

Forrest Nearing

I think they sound good straight piped...

and they're not loud inside the truck either...

Forrest

triplenickel

Really not loud if you add a nice big SS tip to get the tailpipe out past the bed sides.

Bubba_CTD

Yea, I have a 4" turndown at the stock ex.

Forrest Nearing

my 97 w/ 5" straight pipe = LOUD

my buddy's 04.5 w/ 4" straight pipe = not NEARLY as loud!!

riding in it on the highway, you can hardly tell... his is a quad cab automatic if that makes any difference.

Forrest

IA_James

I left the cat on mine, and got rid of the muffler. Sounds nice and mellow, was kinda loud and had a little drone in it until I put the turn down on it, much quieter in the cab and killed the drone almost entirely. That was an unintended plus for me, I was just tired of polishing the soot off the back bumper, so I got the turn down.

Nascarcamper

Let me get this straight, most of you are adding a Stainless turn down at the end and it helps, if not eliminate, the drone. I have the Stainless straight 5" tip that came with my Banks, but I also have drone. It extends out past the fenders but not completely past the dually mud flaps, could this be where the drone is coming from?

blown32

Like the striight pipe sound on mine, no drone to speak off

IA_James

https://www.dieseltruckresource.com/...threadid=51804

There is some info in this thread about killing the drone, alot of others too, some with sucess and some without, but I was able to find this one in reasonably short order.

GotBoost?

I am curious as to when you guys say straight piped are you talking about removing the muffler and that big oval looking(resonator?) thing after the cat?

I was going to remove the muffler and thats it on mine to give it a little more breathing room. Should i remove everything but the cat?

I have an 04 or 04.5 3500 CTD. (Built date is 01/04 on the door.)

Thanks!

Bubba_CTD

Under my truck, I have the CAT and then the muffler (well, did have the muffler...) I didn't have anything else. So when I say I straight pipped mine, I removed the muffler and... installed a straight piece of pipe in it's place. I'm at work now, but I'll try and climb under the truck to snapa shot when I get home.

RUSSELLMAG

I removed my Cat and gutted it, then reinstalled it. Then installed a 18" magnaflow muffler and it sounds great. You will have to have the exhaust changed after the muffler to make it around the axle, but there are one piece systems now that drop in place. It dropped my EGT about 100 degrees after gutting the cat. I would keep it Depending on your State emissions and safty regs. My Sate now has regs in place that have to have cat and muffler on the 2004 Diesel pickups. This is why I kept mine on. Its been great for me, mine as well does not have a drown sound. Hope this was some helpful insight.

IA_James

Mine had just the cat and muffler, I removed the muffler, and left the cat in. Didn't gut or anything, honest!
https://www.dieseltruckresource.com/...cat/500/page/1

That's the new piece of dogleg 4" pipe, the muffler has an offset outlet in it, you could do it cheaper (and I would have if I had thought of it) using a length of flex pipe. Don't have a pic of the turn down, it's an 18" stainless, if you stand directly behind the pass. side rear tire and look forward, it comes out about 3/4 of the way to the edge of the tread on the rear tire, to give you an idea how far it sticks out.