Welcome to the North American Subaru Impreza Owners Club Thursday March 28, 2024
Home Forums Images WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Go Back   NASIOC > NASIOC Technical > Normally Aspirated Powertrain

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 05-21-2018, 11:22 PM   #1
mjm4jc
Scooby Newbie
 
Member#: 241731
Join Date: Mar 2010
Location: Northeast PA
Vehicle:
1997 Impreza Sedan
Turquoise

Default exhaust system help

Hello everyone,

Looking at an 09 Impreza sedan for my daughter. The lady that is selling it said that her son removed the resonator. I only see one catalytic converter on the car........the one that's built in to the manifold. There is a bulge in the middle pipe, but it doesn't look like a converter. I also do not see a bung in the pipe for an O2 sensor in that middle pipe. Wondering if he removed the cat and resonator? Can anyone help?

Thanks!!
* Registered users of the site do not see these ads.
mjm4jc is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 05-22-2018, 12:53 AM   #2
Charlie-III
NASIOC Supporter
 
Member#: 30669
Join Date: Dec 2002
Chapter/Region: Tri-State
Location: USA, North NJ, 07456
Vehicle:
1998 Legacy 2.5GT
Silver Sleeper BK, 5MT

Default

I believe that basic design is similar to the older ones.
The CAT's are forward of the spring loaded donut joint sorta under the front edge of the passengers seat.
After that joint, there is the midpipe with resonator, then the axle back.
Charlie-III is offline   Reply With Quote
Old 05-22-2018, 10:49 AM   #3
mjm4jc
Scooby Newbie
 
Member#: 241731
Join Date: Mar 2010
Location: Northeast PA
Vehicle:
1997 Impreza Sedan
Turquoise

Default

Quote:
Originally Posted by Charlie-III View Post
I believe that basic design is similar to the older ones.
The CAT's are forward of the spring loaded donut joint sorta under the front edge of the passengers seat.
After that joint, there is the midpipe with resonator, then the axle back.
So you're saying for sure that there should be 2 cats? The entire system should have 2 cats and a resonator?? That's pretty much what I've been reading and also what the diagrams are showing. Can anyone else confirm??
mjm4jc is offline   Reply With Quote
Old 05-22-2018, 02:30 PM   #4
GEE-OTTO
Scooby Specialist
 
Member#: 201277
Join Date: Jan 2009
Chapter/Region: MAIC
Location: Northern VA
Vehicle:
2008 08 QSM 5MT LGT
QSM

Default

On that model Impreza the main converter is the one you saw integrated into the manifold it houses the AFR and O2 sensor (one sensor pre and post cat or the first bulge) the secondary cat isn't monitored by a sensor but rather it is a secondary converter that help further clean up exhaust gases once it hits 900F. The resonator is the big flat bulge in the center pipe.

So both sensors are right up front and you can see both by opening the hood and looking down in front of the passenger side timing cover, the harness for both connections is mounted there.
GEE-OTTO is offline   Reply With Quote
Old 05-22-2018, 03:28 PM   #5
Charlie-III
NASIOC Supporter
 
Member#: 30669
Join Date: Dec 2002
Chapter/Region: Tri-State
Location: USA, North NJ, 07456
Vehicle:
1998 Legacy 2.5GT
Silver Sleeper BK, 5MT

Cool

Quote:
Originally Posted by GEE-OTTO View Post
On that model Impreza the main converter is the one you saw integrated into the manifold it houses the AFR and O2 sensor (one sensor pre and post cat or the first bulge) the secondary cat isn't monitored by a sensor but rather it is a secondary converter that help further clean up exhaust gases once it hits 900F. The resonator is the big flat bulge in the center pipe.

So both sensors are right up front and you can see both by opening the hood and looking down in front of the passenger side timing cover, the harness for both connections is mounted there.
Thanks, I don't deal with newer Subaru much.
In general, I think I had it covered, but you provided much better info.
Thanks again.
Charlie-III is offline   Reply With Quote
Old 05-22-2018, 04:40 PM   #6
mjm4jc
Scooby Newbie
 
Member#: 241731
Join Date: Mar 2010
Location: Northeast PA
Vehicle:
1997 Impreza Sedan
Turquoise

Default

Quote:
Originally Posted by GEE-OTTO View Post
On that model Impreza the main converter is the one you saw integrated into the manifold it houses the AFR and O2 sensor (one sensor pre and post cat or the first bulge) the secondary cat isn't monitored by a sensor but rather it is a secondary converter that help further clean up exhaust gases once it hits 900F. The resonator is the big flat bulge in the center pipe.

So both sensors are right up front and you can see both by opening the hood and looking down in front of the passenger side timing cover, the harness for both connections is mounted there.
Thanks everone. Gee-otto.....that was a big help. I went out and looked and saw both O2 sensors on the manifold cat. From what else I see, it appears that the resonator has been removed. Please see pics to confirm that the middle pipe has a secondary cat.
Thanks!
mjm4jc is offline   Reply With Quote
Old 05-22-2018, 04:58 PM   #7
Charlie-III
NASIOC Supporter
 
Member#: 30669
Join Date: Dec 2002
Chapter/Region: Tri-State
Location: USA, North NJ, 07456
Vehicle:
1998 Legacy 2.5GT
Silver Sleeper BK, 5MT

Default

Without doing my own research, midpipes do NOT have CAT's.
Why?
They need heat.
The further from the engine, the cooler the exhaust, thus a CAT won't work.

Go back to my earlier post, CAT's are BEFORE the spring loaded exhaust connection.

How about looking up your exhaust on RockAuto.....see where the bits are?

Have a good day.
Charlie-III 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 07:17 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2024 Axivo Inc.
Copyright ©1999 - 2019, North American Subaru Impreza Owners Club, Inc.

As an Amazon Associate I earn from qualifying purchases.

When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission
Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.