Catless dp on 2006 WRX

Ashmanfish1 · 09-23-2020, 12:14 PM

Hello, I have a 2006 wrx that I got not too long ago and this is my first post on this forum. My car already has an Invidia N1 catback which I believe is the street model not the race one, I want to make my car a bit louder so I decided on getting a catless downpipe as opposed to my stock catted downpipe. My stock one has an 02 sensor at the cat and an 02 sensor bung towards the top pretty close to the turbo but it doesn't have a sensor in it. When I go to purchase a catless dp does it need to have 2 02 sensor spots or just the one where the cat would be? Also do you guys have any recommendations for a dp? I really would like to get one that doesn't throw a code after I install it.

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JarHarms · 09-23-2020, 03:07 PM

Your primary O2 sensor in the up-pipe (pre-turbo). The secondary O2 sensor is after the rear catalyst in your factory downpipe. There should not be any sensor bung on the turbo outlet section on a factory USDM downpipe. If one is there then it would have to be a JDM, aftermarket, or modified downpipe. If there is a bung located there and plugged...it would be a location to add a WBO2 sensor.
If you replace the downpipe on your 2006 you will need tuning to avoid setting any faults. Personally I would opt for a downpipe that has the additional bung for a WBO2 since tuning is involved. Catted -vs- non-catted is your preference and opinions will vary widely on this. Catted will cost more, avoids some minor exh odors, is still non-compliant, and will not save the dolphins as some believe.

...and this does not belong in the interior/exterior mod section...

Ashmanfish1 · 09-23-2020, 03:28 PM

Quote:

Originally Posted by JarHarms

Your primary O2 sensor in the up-pipe (pre-turbo). The secondary O2 sensor is after the rear catalyst in your factory downpipe. There should not be any sensor bung on the turbo outlet section on a factory USDM downpipe. If one is there then it would have to be a JDM, aftermarket, or modified downpipe. If there is a bung located there and plugged...it would be a location to add a WBO2 sensor.
If you replace the downpipe on your 2006 you will need tuning to avoid setting any faults. Personally I would opt for a downpipe that has the additional bung for a WBO2 since tuning is involved. Catted -vs- non-catted is your preference and opinions will vary widely on this. Catted will cost more, avoids some minor exh odors, is still non-compliant, and will not save the dolphins as some believe.

...and this does not belong in the interior/exterior mod section...

Thank you for responding, This did help. Also I am new to the forums and thought that it would go with exterior mods, sorry. For next time where would a question like this go?

JarHarms · 09-23-2020, 03:34 PM

no worries...

I would probably put that in the "Factory 2.5L Turbo Powertrain" section since your WRX is a 2.5L. A mod will likely move this thread there anyways.

subaru_gc8 · 09-23-2020, 04:53 PM

Quote:

Originally Posted by Ashmanfish1

Hello, I have a 2006 wrx that I got not too long ago and this is my first post on this forum. My car already has an Invidia N1 catback which I believe is the street model not the race one, I want to make my car a bit louder so I decided on getting a catless downpipe as opposed to my stock catted downpipe. My stock one has an 02 sensor at the cat and an 02 sensor bung towards the top pretty close to the turbo but it doesn't have a sensor in it. When I go to purchase a catless dp does it need to have 2 02 sensor spots or just the one where the cat would be? Also do you guys have any recommendations for a dp? I really would like to get one that doesn't throw a code after I install it.

you are going to get a cat efficiency codenot ot mention a little over boosting, a un catted down pipe is just a pipe with 2 flanges on it

Suhdude420 · 10-26-2020, 05:21 AM

If you get a catless downpipe you'll also want to tune the car

knesek · 10-27-2020, 01:27 AM

I just got a catted downpipe with to go with my catback and its significantly louder.

09-23-2020, 12:14 PM	#1
Ashmanfish1 Scooby Newbie Member#: 518805 Join Date: Sep 2020 Location: Michigan, USA Vehicle: 2006 Impreza WRX Steel Grey	Catless dp on 2006 WRX Hello, I have a 2006 wrx that I got not too long ago and this is my first post on this forum. My car already has an Invidia N1 catback which I believe is the street model not the race one, I want to make my car a bit louder so I decided on getting a catless downpipe as opposed to my stock catted downpipe. My stock one has an 02 sensor at the cat and an 02 sensor bung towards the top pretty close to the turbo but it doesn't have a sensor in it. When I go to purchase a catless dp does it need to have 2 02 sensor spots or just the one where the cat would be? Also do you guys have any recommendations for a dp? I really would like to get one that doesn't throw a code after I install it. * Registered users of the site do not see these ads.

09-23-2020, 03:07 PM	#2
JarHarms Scooby Specialist Member#: 138994 Join Date: Jan 2007 Chapter/Region: MWSOC Location: DeKalb-ish, IL Vehicle: 2006 WRX, 6MT, 5x114 TMIC, FP blue, ELH	Your primary O2 sensor in the up-pipe (pre-turbo). The secondary O2 sensor is after the rear catalyst in your factory downpipe. There should not be any sensor bung on the turbo outlet section on a factory USDM downpipe. If one is there then it would have to be a JDM, aftermarket, or modified downpipe. If there is a bung located there and plugged...it would be a location to add a WBO2 sensor. If you replace the downpipe on your 2006 you will need tuning to avoid setting any faults. Personally I would opt for a downpipe that has the additional bung for a WBO2 since tuning is involved. Catted -vs- non-catted is your preference and opinions will vary widely on this. Catted will cost more, avoids some minor exh odors, is still non-compliant, and will not save the dolphins as some believe. ...and this does not belong in the interior/exterior mod section... Last edited by JarHarms; 09-23-2020 at 03:14 PM.

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09-23-2020, 03:34 PM	#4
JarHarms Scooby Specialist Member#: 138994 Join Date: Jan 2007 Chapter/Region: MWSOC Location: DeKalb-ish, IL Vehicle: 2006 WRX, 6MT, 5x114 TMIC, FP blue, ELH	no worries... I would probably put that in the "Factory 2.5L Turbo Powertrain" section since your WRX is a 2.5L. A mod will likely move this thread there anyways.

10-26-2020, 05:21 AM	#6
Suhdude420 Scooby Newbie Member#: 500559 Join Date: Apr 2019	If you get a catless downpipe you'll also want to tune the car

10-27-2020, 01:27 AM	#7
knesek Scooby Newbie Member#: 508145 Join Date: Nov 2019 Chapter/Region: MWSOC Vehicle: 2007 WRX Wagon Satin White Pearl	I just got a catted downpipe with to go with my catback and its significantly louder.