OBX Header Install Questions

nti_hazard88 · 05-28-2009, 07:58 PM

Yes, I know.. I know... I can just keep reading and searching the forums. But I'm about ready to throw the OBX EL headers on my 2005 2.5RS, and I have a few questions.

1) Do I NEED an O2 Sensor Extension?

2) Will the headers be a direct fit to the stock cat? (I ask because I have a catback installed, but I'm using the stock cat)

I've been reading quite a bit, but the answers seem to be mixed. So at least, specific to a stock cat on a 2005 2.5RS, can anybody accurately answer these questions? Thanks!

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testify · 05-28-2009, 08:31 PM

I don't know the answer to your question, but +1000 for going to an EL header!

Boxer4Dad · 05-29-2009, 07:58 AM

Quote:

Originally Posted by nti_hazard88

Yes, I know.. I know... I can just keep reading and searching the forums. But I'm about ready to throw the OBX EL headers on my 2005 2.5RS, and I have a few questions.

1) Do I NEED an O2 Sensor Extension?

2) Will the headers be a direct fit to the stock cat? (I ask because I have a catback installed, but I'm using the stock cat)

I've been reading quite a bit, but the answers seem to be mixed. So at least, specific to a stock cat on a 2005 2.5RS, can anybody accurately answer these questions? Thanks!

#1. You will somehow need to extend the wiring for the rear sensor. I bought a 36" extension from Casper's Electronics, but others have cut and spliced their own for less $. The front sensor works with the stock wiring, but you have to undo the rosebud clips that hold it in place to stretch it far enough back.
#2. This header replaces your OEM manifold/header AND the stock cat. It will fit the stock midpipe, so it should fit your catback the same way as your current setup.

Going catless on an '05 also seems to mean you'll have to disable the P0420 CEL, too. I'm still resetting my ECU regularly, since I haven't done this yet, but this is definitely not optimal.

The header IS a great power enhancement, though. There are several informative threads on this header, though, and you should be able to find them to learn more.

Oh, and a boo-yah to someone from the Tri-Cities (former Saginaw resident here)!

nti_hazard88 · 05-29-2009, 03:12 PM

Oh, I see. Damn, I really don't want to go catless. Are there any headers out there that don't delete the cat? I'd prefer EL, but anything that don't kill the cat would be nice. Especially this whole CEL thing... really too lazy to deal with that.

Boxer4Dad · 05-29-2009, 03:50 PM

I think the TWE does what you are looking for, but they are more expensive and harder to find used. TWE = Tech Works Engineering, if you Google them.

nti_hazard88 · 05-29-2009, 07:07 PM

LoL... that's expensive!! Man, thanks for the quick replies though. A last (few) question(s)... How about UEL's? Or hell, anything at all for headers that won't delete my stock cat that's still.. well.. considerably a "budget" option? Of course I don't mean dirt cheap sh** that's going to break down on me, but just anything that's better than stock that won't delete the cat? Thanks, man! And yea, by the way, shout outs right back at ya from the Tri-Cities! Where'd you move to?

RaceFaceXC · 05-29-2009, 08:18 PM

you can have a local shop weld a cat on the OBX headers in place of the resonator that they include with their headers. (resonator is the bulge after the final collector) But to avoid the P0420 CEL you will have to have the front O2 sensor before the cat and the rear O2 sensor after the cat. And even this wont guarantee no P0420 CEL, in fact, I would plan on having to disable or put up with the P0420 CEL with any aftermarket header/cat setup. You could bolt on some borla/replicas to your stock catpipe and cross your fingers, that might avoid a P0420 CEL. but you will be leaving a few hp on the table, more so if you plan on tuning.

nti_hazard88 · 05-29-2009, 09:39 PM

alright, thanks for the info. Just finished doing general research along with answers from this thread. I'll just go ahead and try a set of solutions a buddy and I laid out.

williaty · 05-30-2009, 12:57 AM

From having tried all of the above, and then some, on an 05 RS myself, here's what I have to say:

You WILL have to get the P0420 CEL disabled by a reflash. Any header will cause it, any HFC will cause it. A very, very few don't get it, but don't plan on being that lucky. You can't use ANY mechanical or electronic CEL-fix/MIL-eliminator on an 05, it HAS to be a reflash.

Having used the stock header, the UEL header, and the EL header, man up and get the EL header or go home like a sissy.

Good luck.

renyo · 05-30-2009, 01:06 AM

Edit: Nevermind

nti_hazard88 · 05-30-2009, 03:00 AM

LoL... I'd like to get an EL, because I don't like the rumble to be too deep (yea yea, I know...), but the deal for me is I'm too lazy to deal with not having a cat converter. I'm by no means a tree hugger, but I don't agree with not having one, just because I know how insanely bad that actually is. I may be overstating it, but NOx gases simply are REALLY.. bad...

05-29-2009, 03:12 PM	#4
nti_hazard88 Scooby Newbie Member#: 212379 Join Date: May 2009 Chapter/Region: MWSOC Location: Lansing, MI Vehicle: 2011 WRX Limited 4dr Spark Silver Metallic	Oh Oh, I see. Damn, I really don't want to go catless. Are there any headers out there that don't delete the cat? I'd prefer EL, but anything that don't kill the cat would be nice. Especially this whole CEL thing... really too lazy to deal with that.

05-29-2009, 09:39 PM	#8
nti_hazard88 Scooby Newbie Member#: 212379 Join Date: May 2009 Chapter/Region: MWSOC Location: Lansing, MI Vehicle: 2011 WRX Limited 4dr Spark Silver Metallic	alright, thanks for the info. Just finished doing general research along with answers from this thread. I'll just go ahead and try a set of solutions a buddy and I laid out. Last edited by nti_hazard88; 05-29-2009 at 11:56 PM.

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05-28-2009, 07:58 PM	#1
nti_hazard88 Scooby Newbie Member#: 212379 Join Date: May 2009 Chapter/Region: MWSOC Location: Lansing, MI Vehicle: 2011 WRX Limited 4dr Spark Silver Metallic	OBX Header Install Questions Yes, I know.. I know... I can just keep reading and searching the forums. But I'm about ready to throw the OBX EL headers on my 2005 2.5RS, and I have a few questions. 1) Do I NEED an O2 Sensor Extension? 2) Will the headers be a direct fit to the stock cat? (I ask because I have a catback installed, but I'm using the stock cat) I've been reading quite a bit, but the answers seem to be mixed. So at least, specific to a stock cat on a 2005 2.5RS, can anybody accurately answer these questions? Thanks! * Registered users of the site do not see these ads.

05-28-2009, 08:31 PM	#2
testify * Banned * Member#: 196517 Join Date: Dec 2008 Chapter/Region: NESIC Location: Mcnoobsville Vehicle: 2007 n00b rocket urban grey metallic	I don't know the answer to your question, but +1000 for going to an EL header!

05-29-2009, 03:50 PM	#5
Boxer4Dad Scooby Newbie Member#: 137226 Join Date: Jan 2007 Chapter/Region: MWSOC Location: SE Michigan Vehicle: 2005 Saabaru 2.5i OBP, or Black	I think the TWE does what you are looking for, but they are more expensive and harder to find used. TWE = Tech Works Engineering, if you Google them.

05-29-2009, 07:07 PM	#6
nti_hazard88 Scooby Newbie Member#: 212379 Join Date: May 2009 Chapter/Region: MWSOC Location: Lansing, MI Vehicle: 2011 WRX Limited 4dr Spark Silver Metallic	LoL... that's expensive!! Man, thanks for the quick replies though. A last (few) question(s)... How about UEL's? Or hell, anything at all for headers that won't delete my stock cat that's still.. well.. considerably a "budget" option? Of course I don't mean dirt cheap sh** that's going to break down on me, but just anything that's better than stock that won't delete the cat? Thanks, man! And yea, by the way, shout outs right back at ya from the Tri-Cities! Where'd you move to?

05-29-2009, 08:18 PM	#7
RaceFaceXC Scooby Specialist Member#: 165749 Join Date: Dec 2007 Chapter/Region: South East Location: stupid Florida Vehicle: 2007 No YELLING on the bus!	you can have a local shop weld a cat on the OBX headers in place of the resonator that they include with their headers. (resonator is the bulge after the final collector) But to avoid the P0420 CEL you will have to have the front O2 sensor before the cat and the rear O2 sensor after the cat. And even this wont guarantee no P0420 CEL, in fact, I would plan on having to disable or put up with the P0420 CEL with any aftermarket header/cat setup. You could bolt on some borla/replicas to your stock catpipe and cross your fingers, that might avoid a P0420 CEL. but you will be leaving a few hp on the table, more so if you plan on tuning.

05-30-2009, 12:57 AM	#9
williaty Scooby Guru Member#: 71092 Join Date: Sep 2004 Chapter/Region: MWSOC Location: Delaware County, Ohio Vehicle: 2005 2.5RS Wagon Regal Blue Pearl	From having tried all of the above, and then some, on an 05 RS myself, here's what I have to say: You WILL have to get the P0420 CEL disabled by a reflash. Any header will cause it, any HFC will cause it. A very, very few don't get it, but don't plan on being that lucky. You can't use ANY mechanical or electronic CEL-fix/MIL-eliminator on an 05, it HAS to be a reflash. Having used the stock header, the UEL header, and the EL header, man up and get the EL header or go home like a sissy. Good luck.

05-30-2009, 01:06 AM	#10
renyo Scooby Newbie Member#: 93577 Join Date: Aug 2005 Chapter/Region: MAIC Location: Orlando, unfortunately Vehicle: 98 Impreza	Edit: Nevermind

05-30-2009, 03:00 AM	#11
nti_hazard88 Scooby Newbie Member#: 212379 Join Date: May 2009 Chapter/Region: MWSOC Location: Lansing, MI Vehicle: 2011 WRX Limited 4dr Spark Silver Metallic	LoL... I'd like to get an EL, because I don't like the rumble to be too deep (yea yea, I know...), but the deal for me is I'm too lazy to deal with not having a cat converter. I'm by no means a tree hugger, but I don't agree with not having one, just because I know how insanely bad that actually is. I may be overstating it, but NOx gases simply are REALLY.. bad...