Ecoboost Performance Forum

Ecoboost Performance => Performance => Topic started by: Needmoreboost on November 01, 2013, 02:43:58 PM

Title: Has anyone removed just the third cat? Stock exhaust
Post by: Needmoreboost on November 01, 2013, 02:43:58 PM
I'm looking to do this next week and wanting to make sure this is not going to increase exhaust noise by much.  I will be leaving the stock resonator in place.  So pretty much at the second cat flanges they will be running straight 2.25 pipes in replace of 3rd or 5th (actually) cat.  It looks like most of the catback and mid pipe designs remove these as well with a x type crossover.  But, most of them also remove the resonator (for more exhaust noise) which I do not want.  Anyway, for $85 bucks it seems like a reasonable mod to improve flow just a tad.  I will post some picks when completed. 
Title: Re: Has anyone removed just the third cat? Stock exhaust
Post by: TouchOfEvil on November 01, 2013, 05:29:19 PM
If you are going to do a x-pipe in the cats place i would remove the resonator. It's only purpose is to be an x-pipe for the system. It shouldn't make much difference in sound output.
Title: Re: Has anyone removed just the third cat? Stock exhaust
Post by: shoman04 on November 01, 2013, 07:06:47 PM
I have Catted d-pipe, 2 1/2" x-pipe, 2 1/2 exhaust pipes and dynoMax muffles for the track. In 30min I can re-hang the stock mufflers and all you hear running are the electrical fan running with the sock mufflers on.
http://s1277.photobucket.com/user/shoman04/media/107_0004_zps5f3e7ea0.jpg.html?sort=3&o=43 (http://s1277.photobucket.com/user/shoman04/media/107_0004_zps5f3e7ea0.jpg.html?sort=3&o=43)
Title: Re: Has anyone removed just the third cat? Stock exhaust
Post by: EcoBrick Bob on November 01, 2013, 10:31:51 PM
Think you should do it as planned and report back.  You can always remove the resonator and install an "x-pipe" later. 

I have catted PPE downpipes, the 3rd cat delete and x-pipe instead of resonator, plus Magnaflows on back and it isn't annoying at all. Growls in town but on interstate trips like we are on now, you can hardly hear it.  NO DRONE!  Flex with the large interior area, especially over mufflers is likely noisier inside than a SHO.
Title: Re: Has anyone removed just the third cat? Stock exhaust
Post by: SHODYOU on November 01, 2013, 10:56:07 PM
I would about guarantee you wont hear a difference at all...

I deleted 3rd cat and replaced resonator with a 2.5" magnaflow tru-x muffler and honestly it sounded the same.
I went with an x muffler because I was worried about rasp and drone, and sometimes I wish id have went with a bare x as the car is so quiet.

Even now with catless downpipes and dynomax ultraflo's its still pretty quiet. Just a very mild growl, although its a nice tone, no raspiness and no drone.
Title: Re: Has anyone removed just the third cat? Stock exhaust
Post by: EcoBrick Bob on November 02, 2013, 10:02:22 PM
Same with mine...  At least you can hear it now!!!!
Title: Re: Has anyone removed just the third cat? Stock exhaust
Post by: Needmoreboost on November 03, 2013, 12:05:59 AM
Quote from: SHODYOU on November 01, 2013, 10:56:07 PM
I would about guarantee you wont hear a difference at all...

I deleted 3rd cat and replaced resonator with a 2.5" magnaflow tru-x muffler and honestly it sounded the same.
I went with an x muffler because I was worried about rasp and drone, and sometimes I wish id have went with a bare x as the car is so quiet.

Even now with catless downpipes and dynomax ultraflo's its still pretty quiet. Just a very mild growl, although its a nice tone, no raspiness and no drone.

Thanks guys.  If I dont notice at all that would be great.  ;)
Title: Re: Has anyone removed just the third cat? Stock exhaust
Post by: Excalibur on March 04, 2016, 10:39:36 AM
No pics? Are you able to eliminate the cel you would get doing this with the unleashed tune, or are defoulers a must?
Title: Re: Has anyone removed just the third cat? Stock exhaust
Post by: AJP turbo on March 04, 2016, 11:41:58 AM
Defoulers wont help anything...removing the third cat has no effect on anything since its after the all the o2 sensors...3rd cat is for the planet
Title: Re: Has anyone removed just the third cat? Stock exhaust
Post by: TooFast4SHO on March 04, 2016, 03:52:43 PM
I have the PPE Catted DP's and deleted the resonator and 3rd cat with stock mufflers, it is still REALLY quiet driving around, kinda bumms me out a little.
EhPortal 1.39.5 © 2025, WebDev