Goose85

Say i was to straight pipe my 04.5 cummins. Would I get an increase in Mileage, and or power?

Rambunctious1

Lower egt's and lots of loud. Probably won't see much else.

Lundee

Nice and loud, Some bad drone when towing a cargo trailer @ 2200 rpm. I had no increase in milage but, I put my lift and tires on the day before I stright piped so I may be mistaken.

madhat

I saw maybe .5 gal+, but the loud pedal sounds soooooooo good, that I probably went down 2 mpg.

CUM4X4MINS

Yes I like mine too. I fact I think my cat is about to fall off i think i need to have that checked out.

Allen Hibbs

I did a muffler delete early this week. Sounds great! I can tell that the turbo spools up a bit quicker. No drone at cruise since all i did was delete the muffler. Can't really tell much difference driving it with the windows up. On the outside yes it is much loud when accelerating but not to loud. For the MPG increase i cant tell yet. Have not gone through enough of a tank to tell yet. Here is the pipe i got. https://www.rpmoutlet.com/ezRetail/s...php?msg_id=354
I did have to cut the muffler off to remove it. From the factory the clamps pinch it tighly to the exhaust pipes. All i had to do is take a grinder and make slits on the in and outlets of the muffler and bend them back. Came right off and the new pipe went right on with the factory clamps. hope this helps.

JMalone

I cut mine out the other day. My mileage has went down... I wouldn't have a clue why....

I guess when the new wears off I'll be able to keep my foot out of it, but for now every time I get a chance it seems like I'm romping on it! I definately wish I would have done it months ago.

HotRodK

You guys keep making this decision harder for me. Some say its too loud, some say it sounds great. I just dont want it loud in the cab on a highway trip. That gets old really fast.

cgsafaris

i had my truck all of 30 min and out came muffler and strait pipe love the sound. i love to wait till there is someone walking by and start it and see them jump like someone shoot at them.

Allen Hibbs

As long as you remove just the muffler and leave the cat alone you will not notice inside on the freeway or at cruise.

Jezzhuntin

OK, OK I can't take it anymore. I keep seeing all these threads about str pipen. so say ^&*(^)&*^ other say U*(_&_*(

I have an 03 HO NO CAT, is thing gonna be louder in the cab? It has to be louder outside= louder inside. I want to do it, but I am not sure I can take the deeo constant hum inside while pulling, thru the mtns etc.

HELP

CUM4X4MINS

Yes it will get louder in the cab for you... If you don't think you can take the noise just get you an aftermarket muffler, something a little more free flowing and in turn will be a little louder, but not as loud as the "true" straight pipe. Good luck with the decision.

Michael

Jezzhuntin

thanks, I think my wife would be louder than the exhaust if I got it done then.

CUM4X4MINS

Yes that would not be a good thing..

So you gonna get you an aftermarket muff.?

Michael