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Old 05-02-2009, 11:26 PM   #1
ViperX
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Location: Costa Mesa CA
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2005 2.5rs
The other blue

Default OBX header install. . .

So im a noob and ive been lurking nasioc for a while on info about installing the EL OBX header.

Im about to pull the trigger on buying one for my 05 RS and plan on running it with the stock mid pipe and a SPT cat back i already have. (will this work?)

I understand you need to buy or make a 02 sensor extension in order to do this (if some one knows of a "how to make one of these forum" please point me to it)

Anyways I wanna make sure i have everything i need for this install before I go over to my friends house and rip my car apart (cuz i has no garage)

I've read that this header will give you a CEL. is this a viable way to fix it? or is the o2 bung in the wrong spot or something? -see link-

http://forums.nasioc.com/forums/show...=777117&page=2

Any info or tips on doing this is much appreciated!

I know this topic has been covered i just wanna know i got my stuff together before i start throwing cash at it, ya know

Thanks
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Old 05-03-2009, 12:55 AM   #2
Chi_San
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First off, the OBX EL manifold deletes your first cat, and it extends back further than where the first cat was. If you need the first cat for emissions, then have the resonator that's included with the OBX cut out and have the cat welded in in it's place.

The CEL is from the lack of a cat.

I do believe the O2 sensor bung is further back than the stock location, however I have never played around with an OBX, so I do not know this for sure. I would invest in a 3" and maybe a 6" extention just to be safe.

Consider wrapping it. Buy some DEI header wrap, 2"x50'. I used a small piece of steel wire to hold the wrap in place at the beginning and end of each wrap section. It drastically reduced my underhood temps.

I'll let someone else answer your O2 sensor question in better detail for you, I don't honestly know.
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Old 05-03-2009, 01:16 AM   #3
williaty
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Just buy the O2 sensor extender. You'll need a 30", which is a custom length, but the guys won't charge you any extra for it.

You'll definitely get a P0420 CEL, so you'll need to reflash the car to do that. Good news is that you can do if for about $20 with the Open Source tools.

And be prepared that you have about a 50:50 chance of getting an obnoxious rattle.
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Old 05-03-2009, 05:10 PM   #4
ViperX
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what is the obnoxious rattle associated with? something you can fix or just how it is from buying a knock off header?
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Old 05-03-2009, 05:53 PM   #5
williaty
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No two people have seem to have had the same rattle. Some have been able to fix it, some haven't.
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Old 05-04-2009, 10:46 AM   #6
Boxer4Dad
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It will work with the stock midpipe. You should get a new donut gasket (see your Subie dealer), unless you want to be like me and drive with a big leak for a while. The stock size donut works fine. I got a 36" O2 extension, and it's a little long, but I routed it nicely, and ziptied a bit together to take up the slack. I still have the stock muffler, and I think it is what's making my rattle noise. Too busy to seriously investigate.

I'm running it with no O2 extender at the moment, and it was fine for over 1000 miles on 93 octane. One tank of 87, and the CEL is on. So, I think it's right on the edge of being OK with no additional extension, but I'll eventually do it anyway, so it's not so touchy. Besides, paying for premium fuel (without tuning for it) just to keep the ECU happy bugs my sensibilities, as the RomRaider refrain begins ringing in my ears...
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Old 05-04-2009, 11:41 AM   #7
Jaredwhamilton
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This rattle.. is it when your speeding up? I am running OBX headers, the track pipe and an N1 Catback, and i do have a rattle.. kind of annoying.
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Old 05-04-2009, 07:00 PM   #8
Boxer4Dad
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Mine is near the back of the car, and it happens on and off throttle, but not all the time. Like I said, I think it's the stock muffler, but I don't know yet for sure.
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Old 05-05-2009, 01:12 AM   #9
ViperX
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are you guys that are running an obx happy with the result? would you recommend getting one for my car i beat on everyday? cuz it kinda sounds like a headache with the CEL and the rattles and such.
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Old 05-05-2009, 01:16 AM   #10
williaty
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It's definitely worth the money and the side effects. It's been the best change I've made to the engine.
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Old 05-05-2009, 08:21 AM   #11
Boxer4Dad
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I would ditto that ^. I haven't measured it, but there is definitely more power from about 3000 up to redline, and it sounds more angry now. It was a relatively easy install, too. I like the snapping and popping on downshifts, too, but that's personal preference.
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Old 05-06-2009, 04:28 AM   #12
ViperX
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i ordered my obx and it'll be here in 2 days, im pretty stoked to see the results, thanks for all your help on this guys. ill let you know if i have any issues with the install which sounds pretty strait forward from what i gathered
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Old 05-06-2009, 04:51 AM   #13
ViperX
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Quote:
Originally Posted by williaty View Post
You'll definitely get a P0420 CEL, so you'll need to reflash the car to do that. Good news is that you can do if for about $20 with the Open Source tools.
oh yeah i got more stupid noob questions. how do i go abouts reflashing my car? and whats open source tools?
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Old 05-06-2009, 04:54 AM   #14
williaty
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Quote:
Originally Posted by ViperX View Post
oh yeah i got more stupid noob questions. how do i go abouts reflashing my car? and whats open source tools?
Consult someone who tunes NA subarus....
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Old 05-06-2009, 11:03 PM   #15
ViperX
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I found this on another thread, Is this the correct 02 sensor extension cable i need?

http://www.casperselectronics.com/st...oducts_id=1395

will a 24" work or do i need to go up to 36"
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Old 05-06-2009, 11:03 PM   #16
ViperX
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I found this on another thread, Is this the correct 02 sensor extension cable i need?

http://www.casperselectronics.com/st...oducts_id=1395

will a 24" work or do i need to go up to 36"
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Old 05-06-2009, 11:04 PM   #17
williaty
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I custom ordered a 30", no extra charge, and it's just about perfect.
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Old 05-06-2009, 11:29 PM   #18
ViperX
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Awesome thanks williaty!
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Old 05-07-2009, 12:30 PM   #19
Boxer4Dad
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I got the 36", and part of it had to be zip-tied. It works, though.
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