Is there a way to pass emissions testing w/ turboback exhaust or uncatted dp?

STIstud2k7 · 12-07-2007, 11:31 PM

Hi,

I just recently got a catback exhaust but i really wanted a turbo back exhaust. B/C of emissions testing with a turboback exhaust, i don't want to go through the trouble of changing the exhaust from the turboback to stock exhaust everytime i go to test from emissions in the future.

A friend of mine owns a EVO IX. He has a turboback exhaust. He told me that there is something you can put on to the turboback exhaust and the check engine light won't come on and when getting tested from emissions testing it will show pass. I'm not sure if there is such a thing. IS IT CALLED downpipe adapter? Do you guys know what it is called?

******but. right know i just have a catback exhaust. To do a Cobb ap stage 2 i need to get a catted dp or catless dp? Which catted dp or catless dp gives more power gain? Which dp you guys think i should go for?

***jnprn2003*** · 12-08-2007, 12:31 AM

Just get a catted DP

2MANYCARS · 12-08-2007, 03:57 AM

Just get Cobb's AP, stage 2 flash includes turning off the 2nd O2 sensor, so you don't need to get any mechanical or electrical CEL fix.

STIstud2k7 · 12-16-2007, 07:59 PM

Quote:

Originally Posted by 2MANYCARS

Just get Cobb's AP, stage 2 flash includes turning off the 2nd O2 sensor, so you don't need to get any mechanical or electrical CEL fix.

but. right know i just have a catback exhaust. To do a Cobb ap stage 2 i need to get a catted dp or catless dp? Which catted dp or catless dp gives more power gain? Which dp you guys think i should go for?

twigg107 · 12-16-2007, 08:03 PM

Quote:

Originally Posted by jnprn2003

Just get a catted DP

Its illegal to replace or modify your stock cats Washington state. Kinda funny because 3/4's of the state doesnt require emissions testing.lol

STIstud2k7 · 12-16-2007, 08:47 PM

but. right know i just have a catback exhaust. To do a Cobb ap stage 2 i need to get a catted dp or catless dp? Which catted dp or catless dp gives more power gain? Which dp you guys think i should go for?

wrx650ps · 12-17-2007, 01:56 AM

HKS is a good DP except it has no spot for a WG go bellmouth unless ur doin a EWG

STIstud2k7 · 12-17-2007, 03:53 AM

Quote:

Originally Posted by wrx650ps

HKS is a good DP except it has no spot for a WG go bellmouth unless ur doin a EWG

whats WG and EWG???

diabloadsit · 12-17-2007, 04:00 AM

Quote:

Originally Posted by STIstud2k7

whats WG and EWG???

Waster Gate or External waste gate.

Your turbo can have one in it or you can go external if you would big power with a little less turbo surge. If I could do it over again I would go External.

STIstud2k7 · 12-17-2007, 04:27 AM

Quote:

Originally Posted by diabloadsit

Waster Gate or External waste gate.

Your turbo can have one in it or you can go external if you would big power with a little less turbo surge. If I could do it over again I would go External.

then what kind of dp should i buy? Which brand? Is HKS ok?

StylesJim · 12-17-2007, 06:00 AM

STIstud2k7. Before you go ahead with a cattless read the warnings on COBBS site and dig around for threads talking about blown 07 motors. It is NOT SAFE to run a cattless downpipe without a protune on an 07. Despite what people may say on here... most of them have not followed the 07 issues. It is well documented that the 07s don't take to a cattless setup unless tuned and there are cases of damaged motors because of it. Cobb has a warning on their website stating not to use a cattless downpipe on an 07 with their product. The additional few HP you will gain is not worth the damage you will cause due to overboosting, among other things.

So to answer the question you asked a few times in this thread.. "but. right know i just have a catback exhaust. To do a Cobb ap stage 2 i need to get a catted dp or catless dp? Which catted dp or catless dp gives more power gain? Which dp you guys think i should go for?"

Read the article at the top of this link: cobb . wrx sti accessport . map listing

Go catted. COBB, Perrin, Invidia are just a few good brands.

ScubaSmith7599 · 12-17-2007, 06:27 AM

Ok, to finally answer this poor guys question that he repeated many times and many people still failed to answer.......

I went with a catted DP. You can do either catted or un-catted for stage 2. At the stage II level, running a catless exhaust will probably net you a whole 5 hp with an "off-the-shelf" map. A catless dp will also cause a nasty smell to come from the exhaust, and also turn your rear bumper black over time.

I bought a Maddad V2 divorced-wastegate two piece dp with a high-flow metal substrate cat and a 2.5" exit. Now what does that mean:

Divorced wastegate: Most DP's have a bellmouth where they connect to the turbo. Some people will have problems with boost creep during the winter, caused by the bellmouth. It's not the end of world, but should be avoided. So a divorced-wastegate means that the downpipe has one opening for the turbo outlet, and one exit/pipe for the wastegate. The wastegate pipe then meets up with the DP a few inches down and they merge. This prevents boost creep.

2-piece downpipe: It's made of 2 pieces. The first piece has a cat. I can replace the second, catless piece with the stock, OEM catted piece if I need to for emissions.

Metal substrate cat: These are much longer lasting and higher-flowing than cheaper ceramic substrate cats.

2.5" exit: Uses an OEM donut-style gasket where it meets the cat-back. This allows you to run it with a stock cat-back. people may want to do this because they're upgrading in increments and not buying the whole she-bang in one night. In higher horsepower applications a 2.5" exit can be restrictive. But for stage II with off-the-shelf mapping, it's negligible. Kinda like running a catless exhaust. Yes, it's there, but you can't really tell. And if I ever get around to finding a used Crawford Performance cat-back, or get a nice deal on some other 3" catback, I can simply fork over a few bucks to an exhaust shop to convert the 2.5" to a 3" flange. Or I could swap out the 2nd pipe with a 3" flanged one, thought it'd probably be much more expensive to do that.

I chose mine because I saw it on these forums for sale for $300 and it costs almost $600 brand new. IMO, it's definitely one of the best quality pieces out there. Sure, a generic JDM or JDM knockoff will work(I'm reserving brand-names because you know how it is....everyone's got the best and they'll get offended). But Maddad does it that much better. Rich(THE mad dad) had a thread noting all the differences he put into his downpipes. A slightly smaller inner diameter gives a few more lb/ft of torque, and on his bellmouth'd downpipes the bellmouth extends further down the pipe to help reduce boost creep. Put it this way, even if Maddad products aren't the no-doubt, #1 piece of equipment to buy, there's still none better.

Also, use some common sense. If you can get a great deal on another downpipe that fits your needs, then go for it. Don't get set on 1 specific manufacturer and pass up great deals that will, for the average daily-driver STi, do the same thing.

Let us know if you have any other questions.

StylesJim · 12-17-2007, 10:43 AM

Scuba, with earlier year cars a cattless setup is just fine, but as with every other member who has tried it, a cattless downpipe will give him big problems unless protuned. He should not be running cattless unless he is well educated on the issues 07s face when running cattless.

Tortfeasor STi · 12-17-2007, 10:58 AM

I passed stringent NJ emissions testing and visual inspection by having a catted TBE (Turbo Back Exhaust) and using the Cobb Accessport with their stage 2 OTS (Off The Shelf) map. So, you have a CBE (Cat Back Exhaust) and want to go TBE (Turbo Back Exhaust) so get the cobb accessport and a catted down pipe and you should pass inspection as well.

ScubaSmith7599 · 12-17-2007, 02:28 PM

Styles Jim, you had already mentioned that issue.

I figure that since it had already been covered, I didn't need to write it again.

Nor was I saying that an 07 will run fine with a catless DP and no proper EM. I said a stage II setup can use either a catted or catless DP, which is true.

Please read more carefully before trying to tell me, "I'm going to make him poorer." Yes, when IWSTI emails me subscription updates I get what you write BEFORE you edit it....

12-08-2007, 12:31 AM	#2
*jnprn2003* The Stig II Car: 07 STi, 07 Speed 3.. Fav Mod: EFI Logics tune Location: The Ocean State Posts: 2,063 Join Date: Feb 2007 Trader Rating: (9)	Re: Is there a way to pass emissions testing w/ turboback exhaust or uncatted dp? Just get a catted DP

12-08-2007, 03:57 AM	#3
2MANYCARS Junior STI Driver Car: 2007 Subaru Impreza Fav Mod: Cobb AP Location: Tri-State & Overseas Posts: 99 Join Date: Aug 2007 Trader Rating: (1)	Re: Is there a way to pass emissions testing w/ turboback exhaust or uncatted dp? Just get Cobb's AP, stage 2 flash includes turning off the 2nd O2 sensor, so you don't need to get any mechanical or electrical CEL fix.

12-16-2007, 08:47 PM	#6
STIstud2k7 STI Driver Car: Blue w Gold 07 WRX S Fav Mod: Tune Location: Chicago,IL Posts: 234 Join Date: Apr 2007 Trader Rating: (1)	Re: Is there a way to pass emissions testing w/ turboback exhaust or uncatted dp? but. right know i just have a catback exhaust. To do a Cobb ap stage 2 i need to get a catted dp or catless dp? Which catted dp or catless dp gives more power gain? Which dp you guys think i should go for?

12-17-2007, 01:56 AM	#7
wrx650ps Amateur STI Driver Car: 02 WRX Fav Mod: TE37 Time Attack Edition Posts: 43 Join Date: Sep 2007 Trader Rating: (0)	Re: Is there a way to pass emissions testing w/ turboback exhaust or uncatted dp? HKS is a good DP except it has no spot for a WG go bellmouth unless ur doin a EWG

12-17-2007, 06:00 AM	#11
StylesJim Professional STI Driver Car: 07 OBP STI Fav Mod: Sundays and Boxers Location: VA Posts: 426 Join Date: Feb 2007 Trader Rating: (0)	Re: Is there a way to pass emissions testing w/ turboback exhaust or uncatted dp? STIstud2k7. Before you go ahead with a cattless read the warnings on COBBS site and dig around for threads talking about blown 07 motors. It is NOT SAFE to run a cattless downpipe without a protune on an 07. Despite what people may say on here... most of them have not followed the 07 issues. It is well documented that the 07s don't take to a cattless setup unless tuned and there are cases of damaged motors because of it. Cobb has a warning on their website stating not to use a cattless downpipe on an 07 with their product. The additional few HP you will gain is not worth the damage you will cause due to overboosting, among other things. So to answer the question you asked a few times in this thread.. "but. right know i just have a catback exhaust. To do a Cobb ap stage 2 i need to get a catted dp or catless dp? Which catted dp or catless dp gives more power gain? Which dp you guys think i should go for?" Read the article at the top of this link: cobb . wrx sti accessport . map listing Go catted. COBB, Perrin, Invidia are just a few good brands.

12-07-2007, 11:31 PM	#1
STIstud2k7 STI Driver Car: Blue w Gold 07 WRX S Fav Mod: Tune Location: Chicago,IL Posts: 234 Join Date: Apr 2007 Trader Rating: (1)	Is there a way to pass emissions testing w/ turboback exhaust or uncatted dp? Hi, I just recently got a catback exhaust but i really wanted a turbo back exhaust. B/C of emissions testing with a turboback exhaust, i don't want to go through the trouble of changing the exhaust from the turboback to stock exhaust everytime i go to test from emissions in the future. A friend of mine owns a EVO IX. He has a turboback exhaust. He told me that there is something you can put on to the turboback exhaust and the check engine light won't come on and when getting tested from emissions testing it will show pass. I'm not sure if there is such a thing. IS IT CALLED downpipe adapter? Do you guys know what it is called? *****but. right know i just have a catback exhaust. To do a Cobb ap stage 2 i need to get a catted dp or catless dp? Which catted dp or catless dp gives more power gain? Which dp you guys think i should go for? This ad is not endorsed by this member. Please register or login to hide this ad. Last edited by STIstud2k7 : 12-16-2007 at 08:07 PM. Reason: added another question.*

12-17-2007, 06:27 AM	#12
ScubaSmith7599 Grassroots STI Racer Car: Silver 05 STi Fav Mod: driving school Location: MCB Quantico, Virginia Posts: 581 Join Date: Jul 2007 Trader Rating: (0)	Re: Is there a way to pass emissions testing w/ turboback exhaust or uncatted dp? Ok, to finally answer this poor guys question that he repeated many times and many people still failed to answer....... I went with a catted DP. You can do either catted or un-catted for stage 2. At the stage II level, running a catless exhaust will probably net you a whole 5 hp with an "off-the-shelf" map. A catless dp will also cause a nasty smell to come from the exhaust, and also turn your rear bumper black over time. I bought a Maddad V2 divorced-wastegate two piece dp with a high-flow metal substrate cat and a 2.5" exit. Now what does that mean: Divorced wastegate: Most DP's have a bellmouth where they connect to the turbo. Some people will have problems with boost creep during the winter, caused by the bellmouth. It's not the end of world, but should be avoided. So a divorced-wastegate means that the downpipe has one opening for the turbo outlet, and one exit/pipe for the wastegate. The wastegate pipe then meets up with the DP a few inches down and they merge. This prevents boost creep. 2-piece downpipe: It's made of 2 pieces. The first piece has a cat. I can replace the second, catless piece with the stock, OEM catted piece if I need to for emissions. Metal substrate cat: These are much longer lasting and higher-flowing than cheaper ceramic substrate cats. 2.5" exit: Uses an OEM donut-style gasket where it meets the cat-back. This allows you to run it with a stock cat-back. people may want to do this because they're upgrading in increments and not buying the whole she-bang in one night. In higher horsepower applications a 2.5" exit can be restrictive. But for stage II with off-the-shelf mapping, it's negligible. Kinda like running a catless exhaust. Yes, it's there, but you can't really tell. And if I ever get around to finding a used Crawford Performance cat-back, or get a nice deal on some other 3" catback, I can simply fork over a few bucks to an exhaust shop to convert the 2.5" to a 3" flange. Or I could swap out the 2nd pipe with a 3" flanged one, thought it'd probably be much more expensive to do that. I chose mine because I saw it on these forums for sale for $300 and it costs almost $600 brand new. IMO, it's definitely one of the best quality pieces out there. Sure, a generic JDM or JDM knockoff will work(I'm reserving brand-names because you know how it is....everyone's got the best and they'll get offended). But Maddad does it that much better. Rich(THE mad dad) had a thread noting all the differences he put into his downpipes. A slightly smaller inner diameter gives a few more lb/ft of torque, and on his bellmouth'd downpipes the bellmouth extends further down the pipe to help reduce boost creep. Put it this way, even if Maddad products aren't the no-doubt, #1 piece of equipment to buy, there's still none better. Also, use some common sense. If you can get a great deal on another downpipe that fits your needs, then go for it. Don't get set on 1 specific manufacturer and pass up great deals that will, for the average daily-driver STi, do the same thing. Let us know if you have any other questions.

12-17-2007, 10:43 AM	#13
StylesJim Professional STI Driver Car: 07 OBP STI Fav Mod: Sundays and Boxers Location: VA Posts: 426 Join Date: Feb 2007 Trader Rating: (0)	Re: Is there a way to pass emissions testing w/ turboback exhaust or uncatted dp? Scuba, with earlier year cars a cattless setup is just fine, but as with every other member who has tried it, a cattless downpipe will give him big problems unless protuned. He should not be running cattless unless he is well educated on the issues 07s face when running cattless. Last edited by StylesJim : 12-17-2007 at 11:03 AM.

12-17-2007, 10:58 AM	#14
Tortfeasor STi S204 Racer Car: '08 335xi Coupe Fav Mod: Dinan Reflash Location: Princeton, NJ Posts: 3,490 Join Date: Aug 2005 Trader Rating: (0)	Re: Is there a way to pass emissions testing w/ turboback exhaust or uncatted dp? I passed stringent NJ emissions testing and visual inspection by having a catted TBE (Turbo Back Exhaust) and using the Cobb Accessport with their stage 2 OTS (Off The Shelf) map. So, you have a CBE (Cat Back Exhaust) and want to go TBE (Turbo Back Exhaust) so get the cobb accessport and a catted down pipe and you should pass inspection as well.

12-17-2007, 02:28 PM	#15
ScubaSmith7599 Grassroots STI Racer Car: Silver 05 STi Fav Mod: driving school Location: MCB Quantico, Virginia Posts: 581 Join Date: Jul 2007 Trader Rating: (0)	Re: Is there a way to pass emissions testing w/ turboback exhaust or uncatted dp? Styles Jim, you had already mentioned that issue. I figure that since it had already been covered, I didn't need to write it again. Nor was I saying that an 07 will run fine with a catless DP and no proper EM. I said a stage II setup can use either a catted or catless DP, which is true. Please read more carefully before trying to tell me, "I'm going to make him poorer." Yes, when IWSTI emails me subscription updates I get what you write BEFORE you edit it.... This ad is not endorsed by this member. Please register or login to hide this ad.