Replacement Cat/Exhaust Questions

WillDenham · 04-24-2007, 11:06 AM

Alright, well I've been throwing a random P0420 here and there for the past 2,000 miles or so, and I get it cleared only to have it come back a good 300-400 miles later. I have checked all hoses for vacuum leaks, changed my plugs/wires/ and made sure to reset the ECU.

I have been experiencing what feels to me like hesitation higher up in the power band, also heard it called as bucking a little as it will pause and then come back.

I took off my exhaust from the catalytic converter back and I drove around for a little bit, it seems that the problem has indeed gone away. Now, I'm not too keen on having a super loud exhaust, but I most definatly like to have some tone to it.

Now then, are there any cheaper alternatives to an actual Subaru branded Cat that I could get? Maybe a high flow cat to improve some small HP/Torque numbers, or at least give me a bit of that boxer sound.

I know that the 2.5 can't get a true boxer rumble without headers, but I'd most definatly like to look around and see my options. I do NOT want to run a race pipe, but I'm most definatly interested in looking at my options.

Any suggestions?

piker28 · 04-24-2007, 07:48 PM

cats have a warranty life past the car, call up your local dealer

but aftermarket is stromung, random tech... or buy a cheap ebay hfc and get a muffler shop to make you a pipe with them in it

GC_Anthony · 04-24-2007, 11:29 PM

8 years/80K miles.

ballitch · 04-25-2007, 01:10 AM

do you have emmisions testing in your area requiring you to pass to get tags? if so, you might want to think about a high flow cat instead of getting rid of it. you could get a borla, or borla knock-off. then buy a high flow cat off ebay with 2.25'' diameter pipe and have an exhaust shop weld the HFC in place of the stock cat(1st cat that is)

~Josh~

WillDenham · 04-25-2007, 12:58 PM

No emissions here in Kentucky at all. I really was thinking about a high flow cat instead of just getting rid of it anyway. I don't want something super loud, but I most definatly want some sound.

Would the HFC do anything to sound, other than dampen it a bit compared to running straight back?

Like I said, I'm looking for a bit of a power increase and a nice rumbly sound, well what I can get without doing headers.

PS - Car has 85k on it, so no go on the replacement.

It's a 2002 2.5 RS.

REVNU · 04-25-2007, 01:49 PM

I run a 3" MagnaFlow Spun Metal Cat. Catless was LOUD on my car, and putting in the HFC helped tone it down AND got rid of the smell. The smell didn't bother me much, but I know it would bother the cops if they were behind or next to me.

~ REVNU

Markcjr · 04-25-2007, 02:45 PM

^^^Revnu, are you running a resonator too, or just the hi flow cat? I was wondering if a Hi flow cat would quiet my exhaust down much. Right now i'm running brullen headers, catless, 5zigen fireball cat back. It's real loud now, so I'm debating to go hi flow cat, or both hi flow cat and resonator.

Thanks

mark

legacy1907 · 04-25-2007, 08:07 PM

hi flow cat will make it louder not quieter, atleast my random tech did for sure

WillDenham · 04-26-2007, 01:42 AM

Quote:

Originally Posted by legacy1907

hi flow cat will make it louder not quieter, atleast my random tech did for sure

I'm speaking of quieter compared to catless. Unless for some odd reason it acts like a resonator as well.

REVNU · 04-26-2007, 12:52 PM

I have no resonator, but my muffler is chambered (baffled) so that acts as one I guess. The cat definitely changed the tone of the car it's not as raspy and definitely quieter on the top end. It still gets loud though when I get on it, but that's to be expected.

~ REVNU

Markcjr · 04-26-2007, 03:23 PM

Thanks,
Yeah, I'm catless now, so I figured the hi flow cat might quiet it down, but that I also might need a resonator too.

04-24-2007, 11:06 AM	#1
WillDenham Scooby Newbie Member#: 76687 Join Date: Dec 2004 Chapter/Region: MWSOC Location: Danville, Kentucky Vehicle: 2002 Impreza 2.5 RS Platinum Silver Metalic	Replacement Cat/Exhaust Questions Alright, well I've been throwing a random P0420 here and there for the past 2,000 miles or so, and I get it cleared only to have it come back a good 300-400 miles later. I have checked all hoses for vacuum leaks, changed my plugs/wires/ and made sure to reset the ECU. I have been experiencing what feels to me like hesitation higher up in the power band, also heard it called as bucking a little as it will pause and then come back. I took off my exhaust from the catalytic converter back and I drove around for a little bit, it seems that the problem has indeed gone away. Now, I'm not too keen on having a super loud exhaust, but I most definatly like to have some tone to it. Now then, are there any cheaper alternatives to an actual Subaru branded Cat that I could get? Maybe a high flow cat to improve some small HP/Torque numbers, or at least give me a bit of that boxer sound. I know that the 2.5 can't get a true boxer rumble without headers, but I'd most definatly like to look around and see my options. I do NOT want to run a race pipe, but I'm most definatly interested in looking at my options. Any suggestions?

04-25-2007, 02:45 PM	#7
Markcjr Scooby Newbie Member#: 3973 Join Date: Feb 2001 Chapter/Region: RMIC Location: Truckee, CA Vehicle: 1998 2.5RS mass hole Arcadia Green	^^^Revnu, are you running a resonator too, or just the hi flow cat? I was wondering if a Hi flow cat would quiet my exhaust down much. Right now i'm running brullen headers, catless, 5zigen fireball cat back. It's real loud now, so I'm debating to go hi flow cat, or both hi flow cat and resonator. Thanks mark Last edited by Markcjr; 04-25-2007 at 02:47 PM. Reason: ....

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04-24-2007, 07:48 PM	#2
piker28 Scooby Guru Member#: 22664 Join Date: Aug 2002 Location: north nj	cats have a warranty life past the car, call up your local dealer but aftermarket is stromung, random tech... or buy a cheap ebay hfc and get a muffler shop to make you a pipe with them in it

04-24-2007, 11:29 PM	#3
GC_Anthony Scooby Specialist Member#: 123375 Join Date: Aug 2006 Chapter/Region: Tri-State Location: N. New Jersey Vehicle: 00 Impreza 2.5RS Its all BRP again.	8 years/80K miles.

04-25-2007, 01:10 AM	#4
ballitch Scooby Specialist Member#: 74907 Join Date: Nov 2004 Chapter/Region: NWIC Location: salem, OR Vehicle: 98 cam'd EJ251 Wrx Tranny,slowr than ish	do you have emmisions testing in your area requiring you to pass to get tags? if so, you might want to think about a high flow cat instead of getting rid of it. you could get a borla, or borla knock-off. then buy a high flow cat off ebay with 2.25'' diameter pipe and have an exhaust shop weld the HFC in place of the stock cat(1st cat that is) ~Josh~

04-25-2007, 12:58 PM	#5
WillDenham Scooby Newbie Member#: 76687 Join Date: Dec 2004 Chapter/Region: MWSOC Location: Danville, Kentucky Vehicle: 2002 Impreza 2.5 RS Platinum Silver Metalic	No emissions here in Kentucky at all. I really was thinking about a high flow cat instead of just getting rid of it anyway. I don't want something super loud, but I most definatly want some sound. Would the HFC do anything to sound, other than dampen it a bit compared to running straight back? Like I said, I'm looking for a bit of a power increase and a nice rumbly sound, well what I can get without doing headers. PS - Car has 85k on it, so no go on the replacement. It's a 2002 2.5 RS.

04-25-2007, 01:49 PM	#6
REVNU Scooby Specialist Member#: 82147 Join Date: Mar 2005 Chapter/Region: SCIC Location: Fulas, CA Vehicle: 2005 WRX Sedan Aspen White	I run a 3" MagnaFlow Spun Metal Cat. Catless was LOUD on my car, and putting in the HFC helped tone it down AND got rid of the smell. The smell didn't bother me much, but I know it would bother the cops if they were behind or next to me. ~ REVNU

04-25-2007, 08:07 PM	#8
legacy1907 Scooby Specialist Member#: 94024 Join Date: Aug 2005 Chapter/Region: South East Location: Raleigh, NC Vehicle: 05 WRX CGM 95 YJ Flat black	hi flow cat will make it louder not quieter, atleast my random tech did for sure

04-26-2007, 12:52 PM	#10
REVNU Scooby Specialist Member#: 82147 Join Date: Mar 2005 Chapter/Region: SCIC Location: Fulas, CA Vehicle: 2005 WRX Sedan Aspen White	I have no resonator, but my muffler is chambered (baffled) so that acts as one I guess. The cat definitely changed the tone of the car it's not as raspy and definitely quieter on the top end. It still gets loud though when I get on it, but that's to be expected. ~ REVNU

04-26-2007, 03:23 PM	#11
Markcjr Scooby Newbie Member#: 3973 Join Date: Feb 2001 Chapter/Region: RMIC Location: Truckee, CA Vehicle: 1998 2.5RS mass hole Arcadia Green	Thanks, Yeah, I'm catless now, so I figured the hi flow cat might quiet it down, but that I also might need a resonator too.