Cats or no Cats why do one or the other? - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

lionssfan · 05-02-2011, 09:46 PM

Hi, need help on if I should delete the cats or go with high flow cats. I can't find much information on this subject. And why some have it and some don't. I will be adding a whipple or magna charger with Long tube headers. I already have corsa cat-back exhaust with LS3 engine. thanks

mbrusco103 · 05-02-2011, 10:00 PM

no cats wont pass inspection but since theres no inspection on new cars for 5 years (at least when i live) no cats would be fine for a while. the high flows should be legal but i would check that out for your state. no cats are stinky too so high flows could help with that too

topgun1 · 05-02-2011, 10:02 PM

if you're worried about emission inspections, go cats. If you're not, go no cats. I went with the Solo hi-flow cats where they relocate the o2 sensor further aft to help prevent a CEL code. I also picked up about 20 rwhp with them and great sound improvement too. I'm really happy with the solo's. I have a friend with LT's with no cats and he has gone to 4 mechanics (including mine) and can't pass emissions. At least in NC there are inspections annually and you must pass to renew your registration. maybe it's more leniant in MI. best of luck to you.

Gbusy06 · 05-02-2011, 10:27 PM

Any horse power/torque gains with no cats vs. cats? I am interested as well but I already have the high flow cats.

Synyster · 05-02-2011, 10:33 PM

Quote:

Originally Posted by Gbusy06

Any horse power/torque gains with no cats vs. cats? I am interested as well but I already have the high flow cats.

The differences aren't noticeable, but there may be 2-3rwhp gains without cats. Most people that go without cats do it to save money.

Darth_Emma · 05-02-2011, 10:35 PM

I've heard of people picking up as much as 20 to 25 rwhp by removing the cats from a stock exhaust.

The stock cats are more restrictive than after market high flow cats.

BTW, I have been running high flow cats. The show removed them today so they could put my new electronic exhaust cutouts there (right behind the headers).

lionssfan · 05-02-2011, 10:39 PM

Quote:

Originally Posted by topgun1

if you're worried about emission inspections, go cats. If you're not, go no cats. I went with the Solo hi-flow cats where they relocate the o2 sensor further aft to help prevent a CEL code. I also picked up about 20 rwhp with them and great sound improvement too. I'm really happy with the solo's. I have a friend with LT's with no cats and he has gone to 4 mechanics (including mine) and can't pass emissions. At least in NC there are inspections annually and you must pass to renew your registration. maybe it's more leniant in MI. best of luck to you.

thanks for the info. I don't have to worry about it here in Michigan with inspections. Solo seem to be popular. Do you know if Solo's are better then what comes with most manufactures of long tube headers and thier high flow cats. What was the sound like with your buddies car with no cats? Also do you have headers on yours with the Solo's ?

lionssfan · 05-02-2011, 10:41 PM

Quote:

Originally Posted by mbrusco103

no cats wont pass inspection but since theres no inspection on new cars for 5 years (at least when i live) no cats would be fine for a while. the high flows should be legal but i would check that out for your state. no cats are stinky too so high flows could help with that too

yes I have heard you can get that raw fuel smell...not sure how I feel about that yet

lionssfan · 05-02-2011, 10:43 PM

Quote:

Originally Posted by topgun1

if you're worried about emission inspections, go cats. If you're not, go no cats. I went with the Solo hi-flow cats where they relocate the o2 sensor further aft to help prevent a CEL code. I also picked up about 20 rwhp with them and great sound improvement too. I'm really happy with the solo's. I have a friend with LT's with no cats and he has gone to 4 mechanics (including mine) and can't pass emissions. At least in NC there are inspections annually and you must pass to renew your registration. maybe it's more leniant in MI. best of luck to you.

I would think your fuel economy would suffer without cats because your o2 sensors might be deleted with a tune, but not really sure if there deleted or not with a tune.

steven32708 · 05-02-2011, 10:53 PM

would you have to get a tune if you completely remove the cats. because removing the cats completely is a lot cheaper than getting high flow cats.

lionssfan · 05-02-2011, 11:08 PM

Quote:

Originally Posted by steven32708

would you have to get a tune if you completely remove the cats. because removing the cats completely is a lot cheaper than getting high flow cats.

Yes. your going to throw a code. The post O2 sensor becomes more active without cats if you look at a tec 2. I've seen when the cats burn up and break in piecies and end up in the muffler. The post O2 and pre O2 have the same activity or ......cross counts. The post O2 with cats are always slower then the Pre O2 sensor. hope this makes sense to you. I'm not sure what your loosing when removing cats and having a tune if any. gas milage? Your gaining little more horsepower but not sure what else the advantage if any.

Ovenmitt · 05-03-2011, 12:50 AM

No cats. Less weight, less cost, more power. Always.

Jay23 · 05-03-2011, 02:08 AM

so what about no cats and the muffler delete? would you lose to much back pressure?

lionssfan · 05-03-2011, 02:42 AM

Quote:

Originally Posted by Ovenmitt

No cats. Less weight, less cost, more power. Always.

what about fuel mangament does the ecm still look at 02 sensors with cats removed and tuned? if you know.

05-02-2011, 09:46 PM	#1
lionssfan Drives: 2010 2ss camaro Join Date: Nov 2010 Location: mi Posts: 1,184 View My Garage	Cats or no Cats why do one or the other? Hi, need help on if I should delete the cats or go with high flow cats. I can't find much information on this subject. And why some have it and some don't. I will be adding a whipple or magna charger with Long tube headers. I already have corsa cat-back exhaust with LS3 engine. thanks

05-02-2011, 10:00 PM	#2
mbrusco103 Drives: 2011 2SS/RS (M6) 427 Twin Turbo Join Date: May 2008 Location: NJ Posts: 1,090 View My Garage	no cats wont pass inspection but since theres no inspection on new cars for 5 years (at least when i live) no cats would be fine for a while. the high flows should be legal but i would check that out for your state. no cats are stinky too so high flows could help with that too __________________ 2011 Camaro 2SS/RS ERL 427 M6 TT -AGP Twin Turbo 55/57 .83ar \| ERL 427ci \| Squash Fuel System \| Stainless Works Chambered 3" \| Mcleod RXT \| Factory Hurst Short Throw \| Black Forgestar F14s \| CTS V 6 Piston Brembo \| VIS AMS Carbon Fiber Hood \| Anvil Carbon Fiber Spoiler

05-02-2011, 10:02 PM	#3
topgun1 Drives: 10 SIM 2SS/RS LS3 Join Date: May 2008 Location: Winston-Salem, NC Posts: 1,939 View My Garage	if you're worried about emission inspections, go cats. If you're not, go no cats. I went with the Solo hi-flow cats where they relocate the o2 sensor further aft to help prevent a CEL code. I also picked up about 20 rwhp with them and great sound improvement too. I'm really happy with the solo's. I have a friend with LT's with no cats and he has gone to 4 mechanics (including mine) and can't pass emissions. At least in NC there are inspections annually and you must pass to renew your registration. maybe it's more leniant in MI. best of luck to you. __________________ 5th Gen Camaros of the Carolinas SIM, 2SS/RS LS3 5/7/11 453.9 RWHP 427.5 RWTQ VMS Stage 2.5 Comp Cams kit, Cold Air Inductions intake, ADM race scoop, DT 1 3/4" headers, Solo cats, 3" Magnaflow catback, Pypes cutouts, HP tune, H&R SuperSport springs, Eibach sways/spacers, TexasSpeed UD pulley, LSR tensioner pulley, Barton shifter, skip shift eliminator, powder-coated calipers, R1 concept rotors, StopTech pads, Granatelli wires, Lloyds mats, tint, AAC afterburner taillamps, AAC scanner/sidemarkers, SRP pedals, custom engine cover, black bowties, Ridergraphix hood spears....

05-03-2011, 02:08 AM	#13
Jay23 Drives: 2012 2SS 45th, 2007 VRSCDX Join Date: Jun 2010 Location: Olathe KS Posts: 298	so what about no cats and the muffler delete? would you lose to much back pressure? __________________ 2012 45th Anniversary SS - Borla S Catback, Halltech CAI, Ported TB, Solo High Flows - More to come.....

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05-02-2011, 10:27 PM	#4
Gbusy06 Tap Out Drives: 2011 Camaro SS A6 SGM Join Date: Oct 2010 Location: USA Posts: 189	Any horse power/torque gains with no cats vs. cats? I am interested as well but I already have the high flow cats.

05-02-2011, 10:35 PM	#6
Darth_Emma Psssssssssshhhhhhhhhhhhh! Drives: under contruction Join Date: Nov 2009 Location: Marysville, Ohio Posts: 12,996 View My Garage	I've heard of people picking up as much as 20 to 25 rwhp by removing the cats from a stock exhaust. The stock cats are more restrictive than after market high flow cats. BTW, I have been running high flow cats. The show removed them today so they could put my new electronic exhaust cutouts there (right behind the headers).

05-02-2011, 10:53 PM	#10
steven32708 Drives: 2010 2SS/RS IOM LS3 Camaro Join Date: Aug 2010 Location: Orlando Posts: 28	would you have to get a tune if you completely remove the cats. because removing the cats completely is a lot cheaper than getting high flow cats.

05-03-2011, 12:50 AM	#12
Ovenmitt Account Suspended Drives: 2011 RJT 1SS Join Date: Apr 2010 Location: Fort Lewis, Washington Posts: 730	No cats. Less weight, less cost, more power. Always.