3rd Cat removal? - Club4G Forum : Mitsubishi Eclipse 4G Forums - 2006-2012 Eclipse Authority

Chris05 · June 6th, 2011, 11:29 AM

I've been looking for answers to this question but couldnt find any for the questions I had
I have an auto GS eclipse with an Injen SRI and a Magnaflow Cat back
I just wanted to know the pros and cons of removing the 3rd cat because I noticed it doesnt do much besides restrict airflow.I have stock headers so I still have those two Cats up there and I was wondering if Id still pass emissions tests.

willjones · June 6th, 2011, 11:51 AM

Yo is this jimmies friend chris?? That's crazy

dsm2mivec · June 6th, 2011, 12:07 PM

Ok first off it doesn't restrict air flow.. Second most likely you won't pass emissions.. But why do you wanna remove it

snakeeyes · June 6th, 2011, 12:21 PM

yes it does restrict airflow ! i pass emissions no problem without it here in tn where they are strict.again,refer to rre's dyno sheet if you dont think its restrictive.

meDave · June 6th, 2011, 01:09 PM

If they do a visual inspection like they do in Cali you will not pass.

snakeeyes · June 6th, 2011, 01:16 PM

they had 1 of those mirrors on a stick lookin under my car and i still passed lol

229boss · June 6th, 2011, 01:26 PM

when u get aftermarket headers the 3rd cat goes away anyway right? so how could i upgrade the other 2 cats?

Chris05 · June 6th, 2011, 02:36 PM

Yea it is Jimmies friend Chris haha and I was just curious if taking out the Cat would increase performance or decrease it in any way

joeyb · June 6th, 2011, 02:47 PM

just to be nit-picky - the stock exhaust manifolds are not technically headers. just FYI.

Chris05 · June 6th, 2011, 02:54 PM

What would Joeyb do? :O

akley88 · June 8th, 2011, 06:04 AM

Quote:

Originally Posted by 229boss

when u get aftermarket headers the 3rd cat goes away anyway right? so how could i upgrade the other 2 cats?

the stock manifold has 2 cats in it the 3rd cat is after the resonator closer to the rear of the car.

akley88 · June 8th, 2011, 06:07 AM

Quote:

Originally Posted by Chris05

Yea it is Jimmies friend Chris haha and I was just curious if taking out the Cat would increase performance or decrease it in any way

without any other mods like a header, intake or different muffler you wont notice any power increase from just getting the 3rd cat removed.

snakeeyes · June 8th, 2011, 08:22 AM

Quote:

Originally Posted by akley88

without any other mods like a intake AND different muffler you wont notice any power increase from just getting the 3rd cat removed.

correct !

snakeeyes · June 8th, 2011, 08:24 AM

Quote:

Originally Posted by akley88

the 3rd cat is after the resonator closer to the rear of the car.

false,its right after the down pipe from the manifold

pat_08GT_Spyder · June 8th, 2011, 09:15 AM

Right under the passenger seat... The other thing towards the end of the car is the stock resonator...

Still a Saint · June 8th, 2011, 10:15 AM

Anything that decreases restriction of air flow is going to improve performance because right now the cat is choking our engine. That's what makes RRE headers so desirable... it removes the 2 cats. It will also help a bit with gas mileage.

akley88 · June 9th, 2011, 06:51 AM

Quote:

Originally Posted by snakeeyes

false,its right after the down pipe from the manifold

my bad i forgot the order, i only had the factory exhaust for 3 days before it got switched.

snakeeyes · June 9th, 2011, 11:57 AM

Quote:

Originally Posted by akley88

my bad i forgot the order, i only had the factory exhaust for 3 days before it got switched.

no worries bro

.just didnt want people to be removing the one part that helps keep the rasp out instead of the restricted part.

NitroGlisson · June 9th, 2011, 04:07 PM

I have an interchangeable rear cat and racing cat....the factory cat does hold you back. Put a racing cat on there to pass a visual inspection but if they put one of those anal probes up your rear for emissions you are going to need a real cat for that. That is why I have the two that I can swap back and forth. The real one for the week of inspection and right back to the racing cat for the other 51 weeks

PearlGreenNMean · September 13th, 2011, 09:56 PM

Lol bump I know... but I have the mods in my sig...
If I remove the cat and...
A.) Get straight piping straight to the back, no muffler, would it 1.) Reduce torque because of down pressure loss? 2.) Sound much deeper/higher? 3.) Crackle like ford trucks do without a muffler?
B.) Straight piping to the back, Magnaflow RRE muffler, would it 1.) be a better solution than A?
C.) Replace cat with a "High flow" cat and attach/ detach a magnaflow RRE.
Which one of those would give me the highest gain in torque (preferrably) and/or HP?

Sorry, I just wanna know EVERYTHING before I do it, and why.

FeaRlezZ · September 13th, 2011, 10:40 PM

i have the high flow cat to magnaflow cat-back. it may not b the best for gains (its close) but its definately in my opinion best for sound. VERY deep and smoothe

HomesickAlien · September 13th, 2011, 10:40 PM

Bump for wanting some more opinion on this myself....

PearlGreenNMean · September 13th, 2011, 10:45 PM

Quote:

Originally Posted by HomesickAlien

Bump for wanting some more opinion on this myself....

I thought I typed up a pretty apprehensive request lol.

June 6th, 2011, 11:51 AM	#2 (permalink)
willjones Member Name: Will Jones... Join Date: Jan 2011 Vehicle: 2009 Eclipse GS Posts: 36 Rep Power: 2	Yo is this jimmies friend chris?? That's crazy __________________ just got my 09 eclipse gs. about to start adding upgrades to it as soon as i get my taxes back. keep looking at my posts to see my upgrades

June 6th, 2011, 12:07 PM	#3 (permalink)
dsm2mivec Senior Member Join Date: Oct 2010 Vehicle: 06 Mitsu Eclipse GS Posts: 1,223 Rep Power: 3	Ok first off it doesn't restrict air flow.. Second most likely you won't pass emissions.. But why do you wanna remove it __________________

June 6th, 2011, 12:21 PM	#4 (permalink)
snakeeyes 4g Fanatic Name: Loves haters ! Join Date: Feb 2011 Location: TN hills Vehicle: 09 5 speed manual Posts: 3,078 Rep Power: 5	yes it does restrict airflow ! i pass emissions no problem without it here in tn where they are strict.again,refer to rre's dyno sheet if you dont think its restrictive. __________________ Modified

June 6th, 2011, 01:09 PM	#5 (permalink)
meDave Senior Member Name: David Join Date: Jan 2008 Location: San Francisco, Calif. Vehicle: 06-GS-Titanium Pearl Posts: 1,112 Rep Power: 6	If they do a visual inspection like they do in Cali you will not pass. __________________ Performance: AEM F/IC w/ BilletProof PNP Harness, AEM UEGO Wideband, 2.5" Catback Exhaust w/Dual Outlets, Fujita CAI, Ported Intake Manifold with GT TB Swap, Ralco RZ Short Shifter, RPW Thermal Spacer Kit, RRE SS Race Header Suspension: Evo Brembo Swap, Front: Cusco Strut Tower Bar, Custom Tein Coilovers with D2 Camber Plates Rear: Eibach Sportlines Springs, KYB GR-2 Shocks

June 6th, 2011, 01:16 PM	#6 (permalink)
snakeeyes 4g Fanatic Name: Loves haters ! Join Date: Feb 2011 Location: TN hills Vehicle: 09 5 speed manual Posts: 3,078 Rep Power: 5	they had 1 of those mirrors on a stick lookin under my car and i still passed lol __________________ Modified

		Club4G Forum : Mitsubishi Eclipse 4G Forums - 2006-2012 Eclipse Authority > Performance and Technical > 4G Eclipse GS/SE Specific
3rd Cat removal?

June 6th, 2011, 01:26 PM	#7 (permalink)
229boss Senior Member Name: James Alphadawg Jones Join Date: Jun 2010 Location: jacksonville , florida Vehicle: 2007 eclipse spyder gs Posts: 656 Rep Power: 2	when u get aftermarket headers the 3rd cat goes away anyway right? so how could i upgrade the other 2 cats?

June 6th, 2011, 02:47 PM	#9 (permalink)
joeyb Hard Core 4ger Name: Joe Join Date: Jun 2009 Location: Norman, OK Vehicle: 08 Eclipse GT - SC Posts: 9,236 Rep Power: 14	just to be nit-picky - the stock exhaust manifolds are not technically headers. just FYI. __________________ "Has blower and many modifications." ~347 WHP / ~309 WTQ / ~6 lbs Boost

June 8th, 2011, 09:15 AM	#15 (permalink)
pat_08GT_Spyder dirty frenchie Name: Pat Join Date: Jan 2009 Location: Edmonton, AB Vehicle: 08 GT Spyder 6MT Posts: 5,383 Rep Power: 9	Right under the passenger seat... The other thing towards the end of the car is the stock resonator... __________________ 275whp topless My ride: http://club4g.org/board/members-ride...gt-spyder.html

June 8th, 2011, 10:15 AM	#16 (permalink)
Still a Saint All about the bass. Name: Kevin Join Date: Feb 2010 Location: Frisco Texas Vehicle: 2007/Eclipse/SE Posts: 91 Rep Power: 3	Anything that decreases restriction of air flow is going to improve performance because right now the cat is choking our engine. That's what makes RRE headers so desirable... it removes the 2 cats. It will also help a bit with gas mileage. __________________ MODS: Progress Lowering springs, RRE Underdrive Pulley, Injen SRI, Aero Turbine Axleback, tinted windows 5% in back and sides and front two are 25%, Painted 18" rims, AUX cord in back of Rockford Fosgate, Black Lower door panel stripes, Aftermarket fogs, E4E's Ralliart eyelids, Deleted resonator, Two 12" Rockford Fosgate P1 punch subs with custom box. Soon to be added: RRE Headers.

June 9th, 2011, 04:07 PM	#19 (permalink)
NitroGlisson Soon to be SC'd :) Name: Don Glisson Join Date: Sep 2009 Location: Raleigh, NC Vehicle: 2008 Eclipse GT Posts: 25,369 Rep Power: 30	I have an interchangeable rear cat and racing cat....the factory cat does hold you back. Put a racing cat on there to pass a visual inspection but if they put one of those anal probes up your rear for emissions you are going to need a real cat for that. That is why I have the two that I can swap back and forth. The real one for the week of inspection and right back to the racing cat for the other 51 weeks __________________ Mods: Nitro's Little Girl With Attitude

September 13th, 2011, 09:56 PM	#20 (permalink)
PearlGreenNMean G-TuneD... Name: George Platt Join Date: Mar 2011 Location: Florida, Weirsdale Vehicle: 2009/Eclipse/GS Posts: 1,286 Rep Power: 3	Lol bump I know... but I have the mods in my sig... If I remove the cat and... A.) Get straight piping straight to the back, no muffler, would it 1.) Reduce torque because of down pressure loss? 2.) Sound much deeper/higher? 3.) Crackle like ford trucks do without a muffler? B.) Straight piping to the back, Magnaflow RRE muffler, would it 1.) be a better solution than A? C.) Replace cat with a "High flow" cat and attach/ detach a magnaflow RRE. Which one of those would give me the highest gain in torque (preferrably) and/or HP? Sorry, I just wanna know EVERYTHING before I do it, and why. __________________ HAVE: OBX Exhaust Header+ Mid pipe, TB bypass, Custom CAI, HID Halo Sonar Projectors, Aero 2540i, Dash kit, AEM FIC, D2 Coilovers, 2 JBL GT5-12's powered by Power Acoustik SOON: Turbo Kit... GT25 WANT: Custom painted Rims, 4 bars of sway, and the rest of my fucking turbo kit.

September 13th, 2011, 10:40 PM	#21 (permalink)
FeaRlezZ tUNED. Name: Brian Join Date: Sep 2010 Location: Boston, MA Vehicle: 2009 4G69 Posts: 2,989 Rep Power: 4	i have the high flow cat to magnaflow cat-back. it may not b the best for gains (its close) but its definately in my opinion best for sound. VERY deep and smoothe __________________ AEM FIC / UEGO Wideband + POD / Custom Bolted

September 13th, 2011, 10:40 PM	#22 (permalink)
HomesickAlien Senior Member Name: Jon Join Date: Apr 2011 Location: Wrightsville Beach, NC Vehicle: 2008/Eclipse/Not a GT ; ( Posts: 1,203 Rep Power: 3	Bump for wanting some more opinion on this myself.... __________________ Fujita F5 Cold Air Intake> RRE Headers> WORKS Axleback Exhuast> RRE Underdrive Pulley> Meghan Racing Springs> NOS Octane Booster> Seven Nitros

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode