Welcome to the North American Subaru Impreza Owners Club Thursday December 12, 2019
Home Forums Images WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Go Back   NASIOC > NASIOC Technical > Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo)

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.







* As an Amazon Associate I earn from qualifying purchases. 
* Registered users of the site do not see these ads. 
Reply
 
Thread Tools Display Modes
Old 05-27-2014, 09:22 AM   #1
jefffurbs
Scooby Newbie
 
Member#: 349389
Join Date: Mar 2013
Chapter/Region: NESIC
Location: New England
Vehicle:
2010 Impreza WRX
Silver

Default Need advice on STI Downpipe versus WRX

Hey Guys,
I'll start by saying I am buying an 06 STI turbo back exhaust today for my 04 WRX. I have concerns about using the STI downpipe. I am not buying this exhaust for performance reasons. I'm buying it because my rear catalytic converter is toast and my exhaust is rusted all the way down. I found a good deal on a used turbo back and am jumping on it.
On to the concerns,
I am finding it hard to find information on if this will cause more issues or not. I assume the slightly larger DP will cause my rear 02 sensor to throw a code? Also I think that downpipe is catless correct?
I've seen a few things about modifying how the rear 02 sensor sits to keep the code from being thrown. There is also no way I can afford a Cobb AP either.
Any thoughts or advice? Anyone else done something similar? The more reading I do the more I come up more confused than before.
Thanks

oops edit: the STI DP is catted...my bad
* Registered users of the site do not see these ads.

Last edited by jefffurbs; 05-27-2014 at 10:00 AM.
jefffurbs is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 05-27-2014, 10:51 AM   #2
snake32
Scooby Specialist
 
Member#: 167338
Join Date: Dec 2007
Chapter/Region: TXIC
Location: Texas
Vehicle:
11 Wrx hatch
Dgm

Default

If the Sti exhaust is stock also then there's is no issues at all, downpipes are the same as I've swapped them before in non Sti cars, I think a bracket might be different bc Sti's come with 6spd transmission that is fatter but you don't need to hook that up really.
snake32 is offline   Reply With Quote
Old 05-27-2014, 11:03 AM   #3
jefffurbs
Scooby Newbie
 
Member#: 349389
Join Date: Mar 2013
Chapter/Region: NESIC
Location: New England
Vehicle:
2010 Impreza WRX
Silver

Default

yup all stock from the DP back. It should fit up pretty well (maybe not perfect).
I am more worried about the slightly increased airflow causing my rear 02 sensor to throw a code. Worst comes to worst I can just leave out the STI's downpipe out and keep my wrx one essentially just doing a catback sti swap. If that makes sense.
jefffurbs is offline   Reply With Quote
Old 05-27-2014, 11:07 AM   #4
HinshawWRX
Medium Frank
Moderator
 
Member#: 140114
Join Date: Feb 2007
Chapter/Region: MAIC
Location: Common Sense, VA
Vehicle:
2013 Audi
A6 3.0T

Default

02-07 WRX/STI downpipes are the exact same. One is not larger, one is not catless.

There will not be increased airflow, it's the same pipe.
HinshawWRX is offline   Reply With Quote
Old 05-27-2014, 11:25 AM   #5
jefffurbs
Scooby Newbie
 
Member#: 349389
Join Date: Mar 2013
Chapter/Region: NESIC
Location: New England
Vehicle:
2010 Impreza WRX
Silver

Default

In my haste of research I never even thought to check to see if the downpipes measured up...So it's just from the axle back that is just slightly bigger right?

Regardless thank you for this. That was pretty much the information I needed!
jefffurbs is offline   Reply With Quote
Old 05-27-2014, 12:48 PM   #6
D-Rodman
Scooby Specialist
 
Member#: 110078
Join Date: Mar 2006
Chapter/Region: Tri-State
Location: Long Island N.Y.
Vehicle:
05 Saabaru JDM STi
Black Ver 7 VF48 6sp RA

Default

The intermediate pipe and axle back pipe diameter is a fraction bigger. As stated above, you will have no issues with it not fitting or throwing codes.
D-Rodman is offline   Reply With Quote
Old 05-27-2014, 01:08 PM   #7
jefffurbs
Scooby Newbie
 
Member#: 349389
Join Date: Mar 2013
Chapter/Region: NESIC
Location: New England
Vehicle:
2010 Impreza WRX
Silver

Default

awesome thanks!
jefffurbs is offline   Reply With Quote
Old 05-27-2014, 01:36 PM   #8
Uncle Scotty
*** Banned ***
 
Member#: 16200
Join Date: Mar 2002
Vehicle:
OK buy Nates beans
westcoastroasting.com

Default

any slight size difference is 10000% irrelevant
Uncle Scotty is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

All times are GMT -4. The time now is 12:33 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2019 Axivo Inc.
Copyright ©1999 - 2019, North American Subaru Impreza Owners Club, Inc.

As an Amazon Associate I earn from qualifying purchases.