Does anybody with a BD run without a cat?

LegacySTI · 09-12-2005, 01:40 PM

I was wondering if any BD guys ran without the cat. and if so, do you have any problems with it?

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Perdue · 09-12-2005, 02:07 PM

I ran mine catless for a while. I used the O2 Sensor Spacer from Rallitek and didn't have any problems, CELs, or anything else. It was extremely loud though and I will not do it again.

KD7000 · 09-12-2005, 02:24 PM

Why do you want to run catless?

A good high-flow converter will make about as much power as a "race pipe" but still keep the environment happy.

It'll also keep your car legal- do they test emmissions in your state?

Kraziken · 09-12-2005, 02:31 PM

They do tests in WA, but they just plug in a reader to the OBD port. You can make mods so the computer reads the cat is functioning properly.

From the folks I talked to, even with out the cat, a new subie, might be able to pass a sniff test, but I'm not positive.

I won't run catless because of my conscience. I'm getting a hi-flow turboxs cat for my car.

Gil · 09-12-2005, 03:14 PM

I've been running a gutted cat since i got it in Oct 03. CEL came on a few months later, sometime in the spring.

I replaced the rear O2 sensor cos it looked pretty beatup on visual inspection, and the CEl has been much better behaved. Now, it only comes on when I go from crusing at alittle over 3,000rpm to a little under 3,000. I'm thinking the next thing i might need to do is to replace the front O2 sensor.

Been looking for a hi-flow cat, but haven't been able to find a decent one that i'm able to comfortably afford.

LegacySTI · 09-12-2005, 04:36 PM

The reason I ask is because I have a stromung track pipe and my car is running really rough, the dealership says its because I have no cats and the O2 sensor are overloading the system

Wiscon_Mark · 09-12-2005, 07:08 PM

Quote:

Originally Posted by LegacySTI

The reason I ask is because I have a stromung track pipe and my car is running really rough, the dealership says its because I have no cats and the O2 sensor are overloading the system

sounds like you need something to "fool" your o2 sensor so you stop running rough. You could pick up something like this for cheap.

Gil · 09-12-2005, 10:18 PM

and just what might this "thing" be??

Wiscon_Mark · 09-12-2005, 10:32 PM

Quote:

Originally Posted by Perdue

. I used the O2 Sensor Spacer from Rallitek...

I believe you can also get it from boxer4racing...I got one, because my hi-flow cat just arrived today!

Perdue · 09-13-2005, 05:53 AM

IIRC, Boxer 4 uses electronic bosses to control the o2 sensor, but from what I've heard, these will sometimes still give a CEL with a fully catless system. I'd say get the spacer from Rallitek (Boxer4 might sell'em...too lazy to look). It worked well for me, but what works well for one ECU might piss off the other ECU.

xcntrk75 · 09-13-2005, 07:00 AM

+1 for the spacer... It's what I use and I've never tripped a CAT inefficiency code..

Gil · 09-13-2005, 08:14 AM

I'll give it a shot.

Wiscon_Mark · 09-13-2005, 08:17 AM

Quote:

Originally Posted by Perdue

(Boxer4 might sell'em...too lazy to look)

I dunno if they have it listed on their webpage, but they threw one in for me when i purchased my stromung Hi flow cat from them

Oquipah · 09-13-2005, 08:20 AM

According to boxer4, they have an electronic boss, however will have another option (non-electronic) for the BD's soon. As of last week it was still not on theier website. Give them a call.

Peace,
Oquipah

Gil · 09-13-2005, 12:07 PM

what's an electric boss?? in fact, what's a boss?

Russell Rogers · 09-13-2005, 12:14 PM

go back to ahving cats. NA Subaru's make more power with cats unless the ecu is heavily tuned.

Huffer · 09-13-2005, 01:03 PM

Quote:

Originally Posted by Russell Rogers

go back to ahving cats. NA Subaru's make more power with cats unless the ecu is heavily tuned.

More power, or more torque?

I've never seen a dyno plot with a higher HP reading of cat vs. no cat.

Russell Rogers · 09-13-2005, 01:59 PM

Both. NA subarus do not scavenge exhaust well without cats. Let alone the fact that running no cats in washington state is risky.

Huffer · 09-13-2005, 03:39 PM

Surely scavenging is a byproduct of the exhaust design, not dependent on the inclusion of a catalytic convertor?

(ignoring EPA requirements for the sake of argument)

Perdue · 09-13-2005, 04:36 PM

my car seemed to have more power in the upper rpms actually, this being with EJ22, Borla Headers, Catless with just a canister style muffler. This ended up being way too loud, as I stated above, and really raspy, causing the exhaust to frankly sound like crap. I dunno how much it would differ with the Borla Turbo muffler I'm running now, but I'd rather not find out.

Russell Rogers · 09-13-2005, 04:38 PM

exhaust backpressure has a huge role in scavenging.

Oquipah · 09-13-2005, 06:44 PM

Here's a description of the O2 sensor boss from boxer4:
http://www.teaguesauto.com/exhaust.htm

Gil · 09-13-2005, 07:08 PM

you mean the resistor mod?

Huffer · 09-13-2005, 10:24 PM

Quote:

Originally Posted by Russell Rogers

exhaust backpressure has a huge role in scavenging.

That's correct, but that doesn't mean you have to run catalytic convertors to achieve the same effect.
Pipe diameter, addition/subtraction of bends, resonators etc all contribute to the famed "backpressure" phenomenon.

Do you have any proof that a catless system is less powerful vs. a catted system (ceteris paribus - all things being equal)?

gumball · 09-14-2005, 11:28 AM

I’m not sure why you would want to do this to a daily driver. The cat cuts down carbon monoxide, NOX and, most importantly toxic hydrocarbons. There is some nasty, volatile stuff that comes out of engines- most notably benzene, olefins, formaldehyde, all of which have neurotoxic, carcinogenic, reproductive and developmental toxicity effects. The cat reduces or eliminates a substantial amount of these hydrocarbons, without it you, your kids or whoever are breathing in a daily dose every time you back out of the driveway or pull out of your garage. Not worth it IMHO.

09-12-2005, 01:40 PM	#1
LegacySTI Scooby Newbie Member#: 86621 Join Date: May 2005 Chapter/Region: NWIC Location: Enumclaw, Wa Vehicle: 95 If it brakes Mod it	Does anybody with a BD run without a cat? I was wondering if any BD guys ran without the cat. and if so, do you have any problems with it? * Registered users of the site do not see these ads.

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09-12-2005, 02:07 PM	#2
Perdue Scooby Specialist Member#: 57431 Join Date: Mar 2004 Chapter/Region: MAIC Location: Charleston, WV Vehicle: 98 Legacy GT 04 Dakota QC 4x4	I ran mine catless for a while. I used the O2 Sensor Spacer from Rallitek and didn't have any problems, CELs, or anything else. It was extremely loud though and I will not do it again.

09-12-2005, 02:24 PM	#3
KD7000 Scooby Specialist Member#: 16653 Join Date: Mar 2002 Chapter/Region: NESIC Location: Central MA Vehicle: 2012 Mazda 3 2004 Honda Pilot	Why do you want to run catless? A good high-flow converter will make about as much power as a "race pipe" but still keep the environment happy. It'll also keep your car legal- do they test emmissions in your state?

09-12-2005, 02:31 PM	#4
Kraziken Scooby Specialist Member#: 38629 Join Date: Jun 2003 Chapter/Region: NWIC Location: Northwest Vehicle: 1999 Legacy GT (STI) White	They do tests in WA, but they just plug in a reader to the OBD port. You can make mods so the computer reads the cat is functioning properly. From the folks I talked to, even with out the cat, a new subie, might be able to pass a sniff test, but I'm not positive. I won't run catless because of my conscience. I'm getting a hi-flow turboxs cat for my car.

09-12-2005, 03:14 PM	#5
Gil NASIOC Supporter Member#: 20872 Join Date: Jul 2002 Chapter/Region: Tri-State Location: Rochester, NY Vehicle: t3h rubber-neckers must die!	I've been running a gutted cat since i got it in Oct 03. CEL came on a few months later, sometime in the spring. I replaced the rear O2 sensor cos it looked pretty beatup on visual inspection, and the CEl has been much better behaved. Now, it only comes on when I go from crusing at alittle over 3,000rpm to a little under 3,000. I'm thinking the next thing i might need to do is to replace the front O2 sensor. Been looking for a hi-flow cat, but haven't been able to find a decent one that i'm able to comfortably afford.

09-12-2005, 04:36 PM	#6
LegacySTI Scooby Newbie Member#: 86621 Join Date: May 2005 Chapter/Region: NWIC Location: Enumclaw, Wa Vehicle: 95 If it brakes Mod it	The reason I ask is because I have a stromung track pipe and my car is running really rough, the dealership says its because I have no cats and the O2 sensor are overloading the system

09-12-2005, 10:18 PM	#8
Gil NASIOC Supporter Member#: 20872 Join Date: Jul 2002 Chapter/Region: Tri-State Location: Rochester, NY Vehicle: t3h rubber-neckers must die!	and just what might this "thing" be??

09-13-2005, 05:53 AM	#10
Perdue Scooby Specialist Member#: 57431 Join Date: Mar 2004 Chapter/Region: MAIC Location: Charleston, WV Vehicle: 98 Legacy GT 04 Dakota QC 4x4	IIRC, Boxer 4 uses electronic bosses to control the o2 sensor, but from what I've heard, these will sometimes still give a CEL with a fully catless system. I'd say get the spacer from Rallitek (Boxer4 might sell'em...too lazy to look). It worked well for me, but what works well for one ECU might piss off the other ECU.

09-13-2005, 07:00 AM	#11
xcntrk75 Scooby Specialist Member#: 60224 Join Date: Apr 2004 Chapter/Region: MAIC Location: NOVA Vehicle: 2008 FXT Sports 2.5 Dark Grey Metallic	+1 for the spacer... It's what I use and I've never tripped a CAT inefficiency code..

09-13-2005, 08:14 AM	#12
Gil NASIOC Supporter Member#: 20872 Join Date: Jul 2002 Chapter/Region: Tri-State Location: Rochester, NY Vehicle: t3h rubber-neckers must die!	I'll give it a shot.

09-13-2005, 08:20 AM	#14
Oquipah Scooby Newbie Member#: 9689 Join Date: Aug 2001 Chapter/Region: MAIC Vehicle: 1998 Legacy GT Silver	According to boxer4, they have an electronic boss, however will have another option (non-electronic) for the BD's soon. As of last week it was still not on theier website. Give them a call. Peace, Oquipah

09-13-2005, 12:07 PM	#15
Gil NASIOC Supporter Member#: 20872 Join Date: Jul 2002 Chapter/Region: Tri-State Location: Rochester, NY Vehicle: t3h rubber-neckers must die!	what's an electric boss?? in fact, what's a boss?

09-13-2005, 12:14 PM	#16
Russell Rogers Scooby Specialist Member#: 27261 Join Date: Oct 2002 Chapter/Region: NWIC Location: Wa Vehicle: 1999 www.prjct1.com I'm Ron Burgundy?	go back to ahving cats. NA Subaru's make more power with cats unless the ecu is heavily tuned.

09-13-2005, 01:59 PM	#18
Russell Rogers Scooby Specialist Member#: 27261 Join Date: Oct 2002 Chapter/Region: NWIC Location: Wa Vehicle: 1999 www.prjct1.com I'm Ron Burgundy?	Both. NA subarus do not scavenge exhaust well without cats. Let alone the fact that running no cats in washington state is risky.

09-13-2005, 03:39 PM	#19
Huffer Scooby Specialist Member#: 36735 Join Date: May 2003 Chapter/Region: MWSOC Location: Wellington,NZ / Willoughby,OH Vehicle: 99 GF8 Impreza 2.0 2= 1998 BD + BK Legacy GT	Surely scavenging is a byproduct of the exhaust design, not dependent on the inclusion of a catalytic convertor? (ignoring EPA requirements for the sake of argument)

09-13-2005, 04:36 PM	#20
Perdue Scooby Specialist Member#: 57431 Join Date: Mar 2004 Chapter/Region: MAIC Location: Charleston, WV Vehicle: 98 Legacy GT 04 Dakota QC 4x4	my car seemed to have more power in the upper rpms actually, this being with EJ22, Borla Headers, Catless with just a canister style muffler. This ended up being way too loud, as I stated above, and really raspy, causing the exhaust to frankly sound like crap. I dunno how much it would differ with the Borla Turbo muffler I'm running now, but I'd rather not find out.

09-13-2005, 04:38 PM	#21
Russell Rogers Scooby Specialist Member#: 27261 Join Date: Oct 2002 Chapter/Region: NWIC Location: Wa Vehicle: 1999 www.prjct1.com I'm Ron Burgundy?	exhaust backpressure has a huge role in scavenging.

09-13-2005, 06:44 PM	#22
Oquipah Scooby Newbie Member#: 9689 Join Date: Aug 2001 Chapter/Region: MAIC Vehicle: 1998 Legacy GT Silver	Here's a description of the O2 sensor boss from boxer4: http://www.teaguesauto.com/exhaust.htm

09-13-2005, 07:08 PM	#23
Gil NASIOC Supporter Member#: 20872 Join Date: Jul 2002 Chapter/Region: Tri-State Location: Rochester, NY Vehicle: t3h rubber-neckers must die!	you mean the resistor mod?

09-14-2005, 11:28 AM	#25
gumball Scooby Specialist Member#: 1209 Join Date: Apr 2000 Location: Wheaton, MD	I’m not sure why you would want to do this to a daily driver. The cat cuts down carbon monoxide, NOX and, most importantly toxic hydrocarbons. There is some nasty, volatile stuff that comes out of engines- most notably benzene, olefins, formaldehyde, all of which have neurotoxic, carcinogenic, reproductive and developmental toxicity effects. The cat reduces or eliminates a substantial amount of these hydrocarbons, without it you, your kids or whoever are breathing in a daily dose every time you back out of the driveway or pull out of your garage. Not worth it IMHO.