cat-less exhaust?

[dommk]

Ok, newb question but so what!
I want to get an Apexi N1 or GT Exhaust with Apexi N1 oe GT downpipe, and EVO III Manifold, etc.... BUT i want to run a cat-less system, only problem is, is that i live in chicago, and Emissions say no So what im asking is, is there anyway to run a cat-less system and still pass the test? Oh and which exhaust would be the better choice, N1 or GT?

 

[EclipseTrbo420A]

Well since your obd II then all you would have to do it leave your 02 sensor connected but out of the exhaust, and wrap it in foil and ziptie it under the car. As for which system is better im sure there is many threads on that topic. I myslef would not pay that and have an exhaust shop make me one.

 

[dsmgrimreaper]

both are nice and the only way to pass emissions test is with a high flow cat. i prefer n1

 

[TurkF26]

N1 is better than the GT series. No you cannot pass any emissions test with a sniffer without a cat. just keep your stock DP, and cat handy. The N1 turboback system comes with a reducer so you can hook up your 3 inch Catback to the stock cat.

 

[95blackGsTurbo]

Most state's won't even allow you to test without a cat. I would be a highflow cat for now. I have passed the sniffer test before with a high flow appearing cat that was gutted. It's not hard you just gotta know how to tune your car to get it that way.

 

[Scott_S]

You could always use a cut-out so you can leave your cat in for testing but run an open downpipe at the track or whatever. I bought the N1 muffler and had an exhaust shop put it on, its alot cheaper that way.

 

[1LE]

Cut-outs may not be legal in your area, check before doing that. Hi flow cat is going to let you flow plenty and will keep you out of trouble.

 

[DGajre777]

N1 is the same size and dimensions as the GT. The difference is in material. GT is stainless steel, while N1 can rust but you paint it with high temp paint like I did. You can get the short downpipe and 3" test pipe from RRE (www.roadraceengineering.com) and then get a 3" cat from them too for $150. You put the cat when you have to get emissions and put the test pipe after it is done. Their downpipes/cat and test pipe bolt up to the Apexi N1 or GT exhaust.

How do they check your emissions? Do they do a tail pipe test of the exhaust or just see if the check engine light is on? If it is just the CEL, then you can get an o2 simulator and run a Apexi N1 downpipe without a cat and hook up the o2 simulator. You can get it at www.o2sensorsimulator.com

 

[dommk]

N1 is the same size and dimensions as the GT. The difference is in material. GT is stainless steel, while N1 can rust but you paint it with high temp paint like I did. You can get the short downpipe and 3" test pipe from RRE (www.roadraceengineering.com) and then get a 3" cat from them too for $150. You put the cat when you have to get emissions and put the test pipe after it is done. Their downpipes/cat and test pipe bolt up to the Apexi N1 or GT exhaust.

How do they check your emissions? Do they do a tail pipe test of the exhaust or just see if the check engine light is on? If it is just the CEL, then you can get an o2 simulator and run a Apexi N1 downpipe without a cat and hook up the o2 simulator. You can get it at www.o2sensorsimulator.com

only thing they have ever done is get in it, put it on rollers up to 45mph for a few seconds and thats about it! no poppin the hood, checking lights, etc...

 

[TurkF26]

if you live in cali like me you are.. well not gonna pass.. ever.. anywhere else you probably can pass with anything.

 

[DGajre777]

only thing they have ever done is get in it, put it on rollers up to 45mph for a few seconds and thats about it! no poppin the hood, checking lights, etc...

Then you can probably get away with the Apexi N1 downpipe or the RRE short downpipe and the test pipe. If you fail the test, then get the cat from RRE.

 

[grntalontsi]

if you live in cali like me you are.. well not gonna pass.. ever.. anywhere else you probably can pass with anything.

Yeah here in Jersey, we adopted the same damn cali emissions test. Although my friend told me he passed his wrx with a high flow cat. I waited to pass with my stock exhaust then as soon as I passed I installed my cat-less 3" turbo back Thermal R&D. That was in 2004. I'll go this year, but hopefully I sell it before June.

 

[clipsit]

Does anyone know if I put a test pipe on for the track and then the oem cat back on after if this will mess with my how my car has been tuned? I don't think it will, but I want to make sure. B/c I know that the 2nd O2 sensor is just to tell the ECU that it's there, right? Some one know? Thanks.

 

[EclipseRacing99]

you can pass emissions without a cat. i have to run the sniffer test on mine and ive passed the last 2 years. its not hard its all in how the car is tuned.

 

[Booster2k]

you can pass emissions without a cat. i have to run the sniffer test on mine and ive passed the last 2 years. its not hard its all in how the car is tuned.

Not sure about IL but when I lived in AZ and in GA where its tested (only the ATL metro counties) they do a visual check too and if its not there, no GO. I am with the previous poster, takes about 30 minutes to change it out, hook up stock drive to test, then put cat eliminator back on. Done. I run a cat eleminator type dp and it has a rear o2 bung in it, I have tripped the CEL twice in about 3 yrs. Both on real cold days.

 

[clipsit]

I am also going to do the CEL/resistor mod for the rear O2 sensor too.

 

[fr33b1rth]

listen, if you have any emmissions checks, then just run a cat. it's not like they are that expensive or restrictive anyways, unless you want a super duper ultra high flow one.

good 2.5"
http://store.summitracing.com/defau...1+4294906131+4294867619+4294906122+4294791975

good 3"
http://store.summitracing.com/defau...1+4294906131+4294867619+4294906122+4294791977

way more than you need 2.5"
http://store.summitracing.com/defau...4294867619+4294906122+4294791975&autoview=sku

way more than you need 3"
http://store.summitracing.com/defau...4294867619+4294906122+4294791977&autoview=sku

 

[1LE]

you can pass emissions without a cat. i have to run the sniffer test on mine and ive passed the last 2 years. its not hard its all in how the car is tuned.

Same here, it passed emissions without a cat under a previous owner. Very rarely threw a cat MIL. Since I got it, I *did* put a cat on it though. Car definitely smells better with a cat in place! Not to mention that it IS the law, and they DO setup roadside visual check stations around here!

 

[clipsit]

listen, if you have any emmissions checks, then just run a cat. it's not like they are that expensive or restrictive anyways, unless you want a super duper ultra high flow one

I am just doing the test pipe for the track on Sunday and then switching back. That's why I was asking. I don't plan on driving around w/ it on, just at the track. Thanks guys.

 

[BIGBLAZE79]

I just run my test pipe all year. Then put the cat back in, unplug the battery to turn the check engine light off. Then go to emissions and get tested. My car is AWD so the worst they can do is an idle test. I just make sure to lean out the SAFC before i go in and always passes. When they plug in to the ECU that soon after unplugging the batt, ther computer say's too many unknown variables and they make me do an idle test.

 

[clipsit]

Thanks man. I appreciate the help.

 

[JDP AWD 1g]

just have the exahust welded with flanges for easy cat and test pipe removal. its easy as pie, and isnt really againest the law. because you have the ability to replace the test pipe after the drag strip back to your high flow cat.

 

[clipsit]

I changed out the cat for the test pipe today, before going to the track tomorrow and no CEL b/c my '95 has the O2 sensor after the cat, or maybe I am just lucky!!! Response is alot better. Definitely spools quicker and flows better at 2.5". This ROCKS!!! Although it runs a little rich at idle, that should be fine, but maybe I will take a little fuel out or keep it the same and see what it is like after I throw the cat back on.

 

[grntalontsi]

I run my test pipe all year long. It's way illegal here in Jersey. It will definitely not pass emissions in June. I will have to buy a high flow cat or like I said before, I hope to sell it by then.

The car does run better without the cat because the cat is restrictive. My car doesn't smell that bad, but I tell people to not stand behind it when it's running.