POLL: 2.5" straight pipe w/ cat or w/o cat?

vshockey10 · **Joined:** Tue Apr 19, 2011 9:28 am **Posts:** 59

Post up your opinion. Would you rather go with a full 2.5" exhaust from the turbo back with nothing in the way or do you leave your cat in?

please state your reasoning also what ever it is.

vshockey10 · **Joined:** Tue Apr 19, 2011 9:28 am **Posts:** 59

I should say I am pretty sure with what I want to do I would just like to see what you all have to say

thanks

Vince

flash7210 · **Posted:** Fri Jun 10, 2011 2:48 pm

I kept the cat and went with a straight pipe
that dumps out the side below the rear
passenger door.
The muffler is the most restrictive part.
Most people will say that the cat has little
to no flow restriction.

stoutdog · **Posted:** Fri Jun 10, 2011 4:42 pm

Leave the cat... it has minimal restriction and removing it could be illegal, depending on where you live.

CATCRD · **Posted:** Fri Jun 10, 2011 6:36 pm

Leave the cat. It'll cut down on noise a little bit and keep you legal. Not having one could be a sticking point when you want to sell the jeep eventually.

painemann · **Joined:** Sat Dec 20, 2008 7:02 pm **Posts:** 607

I want to do the exhaust on the crd soon also, has anyone had any issues with the cat and high mileage? I dont want it loud but it would be nice to have a little diesel rumble, what's a good system? I know there are tons of old threads on this but since I'm already typing, figured I'd ask.

warp2diesel · **Posted:** Fri Jun 10, 2011 10:37 pm

I kept the cat but opened up the 2 1/8" Choke Point in the rear cat flange to 2 1/2".
With my Magnaflow 2 1/2" my back pressure was 0.0 PSI after and 5 PSI before.

wfd1350 · **Posted:** Fri Jun 10, 2011 11:17 pm

3 inch with no muffler and no cat. Slightly louder than before but my wife didn't even notice. Sounds awesome with turbo whine.

nickademus · **Joined:** Mon May 09, 2011 2:15 pm **Posts:** 54

kept the cat, magnaflow high flow muffler, quieted it down, no backpressure.

CIMARRON13 · **Posted:** Sat Jun 11, 2011 2:19 pm

I kept the Cat. Took out the reducer and went with 2 1/2 straight pipe. Not loud at all, just a little rumble on start up. You will hear the turbo spool a bit more. No increase in power or MPG that I have noticed but I have only gone through one tank of fuel with A/C running for the first time this summer. It's hotter than normal at the moment in Austin.

SLS · **Posted:** Sat Jun 11, 2011 6:37 pm

CRD exhaust stuff from different sources.
Here are a couple of links:
http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?t=44669

The catalytic converter, and one is an install with some sound recordings.
http://liberty.eurekaboy.com/magnaflow.htm

Jeep Liberty CRD Muffler Delete Sound Clip:
http://youtu.be/VwYVMU5x-Fk

Jeep 05 CRD 3" straight pipe turbo back:
http://youtu.be/7r1iS-KD5GI

Jeep Liberty 2.8 CRD, Magnaflow Muffler, Cat delete 2.5" pipe, dual wall 3"
http://youtu.be/8VYhC8tfVvc

flash7210 · **Posted:** Sat Jun 11, 2011 7:27 pm

Is there anything special that can be done with the turbo downpipe?
Is the stock shape and profile the best that can be done?

vshockey10 · **Joined:** Tue Apr 19, 2011 9:28 am **Posts:** 59

well I left the cat as I planned on doing from the beginning. But the guy put in a 2.75" pipe and just slide it over the ends he cut. Im not sure I like the sound of it though. It is almost to low pitched almost sounds boggy

could that be because of how he deleted the muffler?

irollgen4s · **Posted:** Sun Jun 12, 2011 10:31 pm

http://www.youtube.com/watch?v=xlOBuliKo_M

This is mine, first clip is the bone stock exhaust. Second clip is a muffler delete. Kept the "oxidation catalyst" on. Overall, love the way it sounds and the turbo whistle alone made it worth it.

dgeist · **Posted:** Sun Jun 12, 2011 10:57 pm

I'm in the "keep the cat; get rid of anything else that isn't 2.5" pipe/flange" crowd. Noticeably better performance than stock, probably the cheapest option to do, and still legal (at least in my state).

Dan

CATCRD · **Posted:** Mon Jun 13, 2011 8:05 pm

irollgen4s wrote:

http://www.youtube.com/watch?v=xlOBuliKo_M

This is mine, first clip is the bone stock exhaust. Second clip is a muffler delete. Kept the "oxidation catalyst" on. Overall, love the way it sounds and the turbo whistle alone made it worth it.

Sounds great now. Any drone at highway speeds?

irollgen4s · **Posted:** Mon Jun 13, 2011 8:35 pm

With f37, minor. I usually have the radio on anyway but even with it off its not bad at all. its better then just listening to the wind anyway... Ever since i got it i've been using the skinny pedal substantially more :mrgreen:

805gregg · **Posted:** Mon Jun 13, 2011 10:12 pm

You've got to be kidding the muffler only costs about 1-2 HP, just get a good one, who wants to hear you exhaust noise, not me and I don't want to hear your's ether. Thanks.

irollgen4s · **Posted:** Mon Jun 13, 2011 11:04 pm

I didnt do it for power, i WANT to hear my exhaust. It's not even loud it just sounds ten times better. And now that i think back i wish i cut off the stupid oxidation catalyst, its gunna go bad eventually and it wouldve saved me money in the long run.

flash7210 · **Posted:** Tue Jun 14, 2011 8:38 am

805gregg wrote:

You've got to be kidding the muffler only costs about 1-2 HP, just get a good one, who wants to hear you exhaust noise, not me and I don't want to hear your's ether. Thanks.

Seriously?
Don't knock it till you try it. :roll:

The muffler delete is one of the cheapest mods you can do that actually
provides some performance benefit.
Inside the cab is no noisier than with the muffler.
Outside it sounds like a tractor and is still quieter than any Harley Davidson.

POLL: 2.5" straight pipe w/ cat or w/o cat?

Who is online