Welcome to the North American Subaru Impreza Owners Club Saturday October 25, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
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.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 02-05-2008, 12:20 PM   #1
ozzy370
Scooby Specialist
 
Member#: 162469
Join Date: Oct 2007
Chapter/Region: RMIC
Location: Suba Performance, Denver, CO
Vehicle:
2003 WRX wagon
special sauce

Default Rear O2 Sensor Code P0037

Searched my butt off on this, found a ton of info, but still have some questions.

Car- 2003 wrx wagon 108,000 miles
mods-
Vf30
sti pink injectors
255 fuel pump
sti top mount
perrin up pipe
full borla CATLESS exaust (wish i had cats but car came with it.)
cobb AP v1.0 with protune
hallman MBC
resonator delete
k&n filter

Now with that said i have a CEL b/c of code P0037. Rear O2 sensor( which i think is just a NB).
Since the current conditions here in colorado (had 36in of snow in the last 7 days) have prevented me from getting under the car to look @ the wires to visually inspect it, i know if the wires are bad ill just get a ne sensor no big deal.....

but if the wires are OK and the sensor itself is bad, is that b/c of the catless exaust or did it just go bad? Im trying to figure out is this something i should replace or will it just throw the code again after i put a new sensor in.

any help would be great.
* Registered users of the site do not see these ads.
ozzy370 is offline   Reply With Quote
Old 02-05-2008, 02:36 PM   #2
Haelan
Scooby Specialist
 
Member#: 151045
Join Date: Jun 2007
Location: NW Indiana
Vehicle:
2013 Subaru STI
CBP

Default

Heated O2 sensors have a lifespan of roughly 100,000 miles. Seeing that you have 108k and assuming it's the original sensor--it might have just been it's time to die.

P0037 is REAR O2 SENSOR HEATER CONTROL CIRCUIT LOW (BANK 1 SENSOR 2)

The heater element of the sensor could be toast or it could be shorted to ground if your wires were somehow burnt. Either way replacing the sensor with the attached pigtail / wire harness will fix your issue.
Haelan is offline   Reply With Quote
Old 02-05-2008, 04:05 PM   #3
hondaeater69
Scooby Guru
 
Member#: 60324
Join Date: Apr 2004
Location: a pillow.
Default

that code should have been defeated by your protune. contact your tuner.
hondaeater69 is offline   Reply With Quote
Old 02-05-2008, 04:34 PM   #4
ozzy370
Scooby Specialist
 
Member#: 162469
Join Date: Oct 2007
Chapter/Region: RMIC
Location: Suba Performance, Denver, CO
Vehicle:
2003 WRX wagon
special sauce

Default

as soon as i do i reflash it goes away for all of 10 seconds and then pops back on. from what i have been reading that code is not taken away by the AP. But i really have no clue. i trush my tuner but i will give him a call
ozzy370 is offline   Reply With Quote
Old 02-05-2008, 04:49 PM   #5
ozzy370
Scooby Specialist
 
Member#: 162469
Join Date: Oct 2007
Chapter/Region: RMIC
Location: Suba Performance, Denver, CO
Vehicle:
2003 WRX wagon
special sauce

Default

by the way i had this code before the protune. if i did a reflash with AP with a generic cobb map (vf30 with 91 oct) it would go away until i would have a boost cut @ 19 psi and was running rich (10:1). the car is now running 16psi max and of course does not have the boost cut and has been leaned out to about 11:1
ozzy370 is offline   Reply With Quote
Old 02-05-2008, 07:01 PM   #6
hondaeater69
Scooby Guru
 
Member#: 60324
Join Date: Apr 2004
Location: a pillow.
Default

well running catless that sensor is useless. all codes associated with that sensor should be defeated.
hondaeater69 is offline   Reply With Quote
Old 02-05-2008, 07:12 PM   #7
ozzy370
Scooby Specialist
 
Member#: 162469
Join Date: Oct 2007
Chapter/Region: RMIC
Location: Suba Performance, Denver, CO
Vehicle:
2003 WRX wagon
special sauce

Default

so i really should not replace the sensor? and just have the code masked?
ozzy370 is offline   Reply With Quote
Old 02-06-2008, 11:03 AM   #8
hondaeater69
Scooby Guru
 
Member#: 60324
Join Date: Apr 2004
Location: a pillow.
Default

Quote:
Originally Posted by ozzy370 View Post
so i really should not replace the sensor? and just have the code masked?

you realize that particular sensor has one function... to monitor the efficency of your DP cat. you don't have any, as you know . i don't even have my rear 02 sensor plugged in
hondaeater69 is offline   Reply With Quote
Old 02-06-2008, 11:14 AM   #9
Haelan
Scooby Specialist
 
Member#: 151045
Join Date: Jun 2007
Location: NW Indiana
Vehicle:
2013 Subaru STI
CBP

Default

Quote:
Originally Posted by hondaeater69 View Post
you realize that particular sensor has one function... to monitor the efficency of your DP cat. you don't have any, as you know . i don't even have my rear 02 sensor plugged in
+1

I agree, it's really only there for emissions purposes. It ensures you don't have any exhaust gases bypassing the cats between the front and rear O2 sensors via a leak.

Being catless you can run without the rear sensor. I'm the type who wants to make sure everything on the car is functioning the way it is supposed to, or it bugs the crap out of me.
Haelan is offline   Reply With Quote
Old 02-06-2008, 04:07 PM   #10
ozzy370
Scooby Specialist
 
Member#: 162469
Join Date: Oct 2007
Chapter/Region: RMIC
Location: Suba Performance, Denver, CO
Vehicle:
2003 WRX wagon
special sauce

Default

yeah. i really just cant stand that CEL staring at me. i no it no big deal but im just trying the most efficent way to deal with it so it wont come back on
ozzy370 is offline   Reply With Quote
Old 02-06-2008, 04:15 PM   #11
Haelan
Scooby Specialist
 
Member#: 151045
Join Date: Jun 2007
Location: NW Indiana
Vehicle:
2013 Subaru STI
CBP

Default

If you're using the Cobb AP with the VF30 91 Oct map these codes should be defeated:

CEL Codes Defeated [WHEN USING AS BASE MAP] (** means new to latest revision):
P0037 - Rear O2 Sensor Heater Control Circuit Low
P0038 - Rear 02 Sensor Heater Control Circuit High
P0137 - Rear O2 Sensor Low Voltage
P0138 - Rear O2 Sensor High Voltage
P0139 - Rear O2 Sensor Circuit Slow Response
P0420 - Catalyst System Efficiency Below Threshold
P0545 - Exhaust Gas Temperature Sensor Circuit Low
P0546 - Exhaust Gas Temperature Sensor Circuit High
P1301 - Misfire Detected (High Temperature Exhaust Gas)
P1312 - Exhaust Gas Temperature Sensor Malfunction
P1544 - Exhaust Gas Temperature Too High

I wonder why it is still showing up...did your tuner somehow re-enable it?
Haelan is offline   Reply With Quote
Old 02-06-2008, 07:18 PM   #12
ozzy370
Scooby Specialist
 
Member#: 162469
Join Date: Oct 2007
Chapter/Region: RMIC
Location: Suba Performance, Denver, CO
Vehicle:
2003 WRX wagon
special sauce

Default

It is a protune. Thats what im thinking, he almost had to. b/c before i had the tune i was using the generic cobb map and it would disappear until i would hit boost cut then i would get it again. now if i reflash with base map on the pro tune it stays off for 10 seconds and comes back up



???? need to talk to tuner ........
ozzy370 is offline   Reply With Quote
Old 02-06-2008, 07:18 PM   #13
hondaeater69
Scooby Guru
 
Member#: 60324
Join Date: Apr 2004
Location: a pillow.
Default

Quote:
Originally Posted by Haelan View Post
If you're using the Cobb AP with the VF30 91 Oct map these codes should be defeated:

CEL Codes Defeated [WHEN USING AS BASE MAP] (** means new to latest revision):
P0037 - Rear O2 Sensor Heater Control Circuit Low
P0038 - Rear 02 Sensor Heater Control Circuit High
P0137 - Rear O2 Sensor Low Voltage
P0138 - Rear O2 Sensor High Voltage
P0139 - Rear O2 Sensor Circuit Slow Response
P0420 - Catalyst System Efficiency Below Threshold
P0545 - Exhaust Gas Temperature Sensor Circuit Low
P0546 - Exhaust Gas Temperature Sensor Circuit High
P1301 - Misfire Detected (High Temperature Exhaust Gas)
P1312 - Exhaust Gas Temperature Sensor Malfunction
P1544 - Exhaust Gas Temperature Too High

I wonder why it is still showing up...did your tuner somehow re-enable it?

protuner's often have their own base maps they start with, with their own parameters. chances are, for whatever reason, the tuner didn't have that DTC defeated. it just takes a simple phone call, email, reflash and you're done.
hondaeater69 is offline   Reply With Quote
Old 02-22-2008, 04:42 PM   #14
ozzy370
Scooby Specialist
 
Member#: 162469
Join Date: Oct 2007
Chapter/Region: RMIC
Location: Suba Performance, Denver, CO
Vehicle:
2003 WRX wagon
special sauce

Default

OK.... called tuner... got new maps. reflashed with base and realtime maps. CEL defeated. went on 10 min drive... everything ok. (this was on a wends night if it matters)

so i go and start it today (friday) after 5 seconds of running...not driving the CEL throws again. so i reflash with just the real time map again. still have CEL. im trying not to reflash basemaps due to limited basemap flashes? so i have heard.


ANY HELP!!

i am also waiting on my tuners resonse to this
ozzy370 is offline   Reply With Quote
Old 02-22-2008, 10:28 PM   #15
SDgoods
Scooby Specialist
 
Member#: 156130
Join Date: Aug 2007
Chapter/Region: SCIC
Location: North County San Diego
Vehicle:
2001 s2000

Default

my rear 02 went bad (i think from my catted dp) and i just simply replaced the sensor and cleared the code with a universal scanner... all good now. (duno if that helps but that is a simple solution)
SDgoods is offline   Reply With Quote
Old 02-23-2008, 05:09 AM   #16
561wrx
Scooby Specialist
 
Member#: 166427
Join Date: Dec 2007
Chapter/Region: South East
Location: boynton bch, fl
Vehicle:
03 wrx

Default

[IMG]file:///C:/DOCUME%7E1/Stephen/LOCALS%7E1/Temp/moz-screenshot.jpg[/IMG][IMG]file:///C:/DOCUME%7E1/Stephen/LOCALS%7E1/Temp/moz-screenshot-1.jpg[/IMG]Step 1 - 5
Step 6 - 7
561wrx is offline   Reply With Quote
Old 02-24-2008, 01:37 PM   #17
ozzy370
Scooby Specialist
 
Member#: 162469
Join Date: Oct 2007
Chapter/Region: RMIC
Location: Suba Performance, Denver, CO
Vehicle:
2003 WRX wagon
special sauce

Default

561wrx

what was that post ?
ozzy370 is offline   Reply With Quote
Old 02-24-2008, 02:08 PM   #18
hondaeater69
Scooby Guru
 
Member#: 60324
Join Date: Apr 2004
Location: a pillow.
Default

Quote:
Originally Posted by ozzy370 View Post
OK.... called tuner... got new maps. reflashed with base and realtime maps. CEL defeated. went on 10 min drive... everything ok. (this was on a wends night if it matters)

so i go and start it today (friday) after 5 seconds of running...not driving the CEL throws again. so i reflash with just the real time map again. still have CEL. im trying not to reflash basemaps due to limited basemap flashes? so i have heard.


ANY HELP!!

i am also waiting on my tuners resonse to this

R/T reflashes don't help with defeating CEL's. that logic is contained in the base map. don't worry about using all your flashes, you NEVER WILL. given that, if it didn't work the first time, it wont work the second time. either you flashed the wrong map, or they didn't fix it.

btw, w hen you flash a base it contains all R/T information, no need to waste time flashing the R/T right after you flash the base. the only time you would flash a diff R/T map is if it contained different parameters than the base map... eg a high boost, 100 oct tune etc.
hondaeater69 is offline   Reply With Quote
Old 02-24-2008, 02:11 PM   #19
hondaeater69
Scooby Guru
 
Member#: 60324
Join Date: Apr 2004
Location: a pillow.
Default

i'm going to PM you my email. email me back the map and i will see if i can open it in street tuner to see if they did indeed defeat that code. if you want...
hondaeater69 is offline   Reply With Quote
Old 02-24-2008, 07:02 PM   #20
ozzy370
Scooby Specialist
 
Member#: 162469
Join Date: Oct 2007
Chapter/Region: RMIC
Location: Suba Performance, Denver, CO
Vehicle:
2003 WRX wagon
special sauce

Default

thanks very much, email sent
ozzy370 is offline   Reply With Quote
Old 02-25-2008, 05:27 PM   #21
ozzy370
Scooby Specialist
 
Member#: 162469
Join Date: Oct 2007
Chapter/Region: RMIC
Location: Suba Performance, Denver, CO
Vehicle:
2003 WRX wagon
special sauce

Default

talked to tuner today. said he deleted code P0420 not code P0037. he said that he didnt want to delete it b/c it was an important code and that the o2 sensor needs to be replaced. i will replace the o2 sensor but i wil not be able to till this summer. but i have also heard that that rear o2 is a narrowband and that it really is not important and is essentailly there for emissions. Is this correct?
ozzy370 is offline   Reply With Quote
Old 02-28-2008, 02:51 PM   #22
hondaeater69
Scooby Guru
 
Member#: 60324
Join Date: Apr 2004
Location: a pillow.
Default

it's not important at all, it is there to monitor cat efficiency, and you don't have any . there's no need for me to look at the maps, he admitted the problem. that code does not mean the sensor is bad. ask him again, nicely to remove the code, that you will accept all liability. My oem rear 02 sensor isn't even plugged in

FYI Cobb's map's defeat this code also. and i wouldn't go about replacing the sensor... that doesn't make any sense. unplug the sensor from the harness, get the right map, reflash and you're done.
hondaeater69 is offline   Reply With Quote
Old 02-28-2008, 04:20 PM   #23
ozzy370
Scooby Specialist
 
Member#: 162469
Join Date: Oct 2007
Chapter/Region: RMIC
Location: Suba Performance, Denver, CO
Vehicle:
2003 WRX wagon
special sauce

Default

i also heard that 02-03 and 04 up are a bit different. is there any truth to the different ecu and what the rear 02 sensor is for?
ozzy370 is offline   Reply With Quote
Old 02-28-2008, 04:20 PM   #24
ozzy370
Scooby Specialist
 
Member#: 162469
Join Date: Oct 2007
Chapter/Region: RMIC
Location: Suba Performance, Denver, CO
Vehicle:
2003 WRX wagon
special sauce

Default

i also heard that 02-03 and 04 up are a bit different. is there any truth to the different ecu and what the rear 02 sensor is for?
ozzy370 is offline   Reply With Quote
Old 02-28-2008, 04:36 PM   #25
hondaeater69
Scooby Guru
 
Member#: 60324
Join Date: Apr 2004
Location: a pillow.
Default

the ecu's are differnet, but the sensor's function is the same.
hondaeater69 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

Similar Threads
Thread Thread Starter Forum Replies Last Post
Front O2 sensor vs Rear O2 sensor (MY00 RS) Jewbaru Service & Maintenance 3 07-29-2012 10:14 PM
Driving with an O2 sensor code Gonz#75 Rocky Mountains Impreza Club Forum -- RMIC 24 07-17-2009 06:07 PM
FS (OH): WRX/STi rear o2 sensor, MAF sensor, MAP sensor coolblue05 Engine/Power/Exhaust 14 07-07-2009 02:52 PM
FS: 05 STi Front A/F Sensor and rear o2 Sensor - Brand new in box! Timmy Burns Engine/Power/Exhaust 3 01-24-2008 10:38 AM
how to get rid of rear o2 sensor code with Utec and Tuner in a 05? bustaman Engine Management & Tuning 6 06-13-2005 04:59 PM


All times are GMT -4. The time now is 03:17 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2014 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.