Welcome to the North American Subaru Impreza Owners Club Saturday April 19, 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 > 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.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 11-11-2001, 12:37 AM   #1
Niloc
Scooby Newbie
 
Member#: 3296
Join Date: Dec 2000
Location: The Hamptons NY usa
Vehicle:
99 impreza RS
Blue

Default W/W an O2 sensor to read slow & inaccurate?

Does anyone have a clue what would cause an O2 sensor to read slow & inaccurate? My car is obviously running rich ( black smoke) but my O2 reads lean & is slow to react. I have an A/F gauge & it use to give the pritty light show that they do, bounce back & forth; pegging on rich at wide open throttle & leaning out on deceleration. Now it hancs out in the lean all the time, unless I'm crusing at 50 or up; then it goes up a little. Never rich? Not even at W/O throttle, it actually show's that it leans out? The CPU reads the same as the gauge. I am 100% positive that the gauge & sensor work. Any ideas???
* Registered users of the site do not see these ads.
Niloc is offline   Reply With Quote
Old 11-11-2001, 01:05 AM   #2
Kevin Thomas
Street Racing Instructor
Moderator
 
Member#: 110
Join Date: Jul 1999
Location: 1997 OBS, 1996 SVX, 1988 RX
Vehicle:
1989 1989 XT6

Default Ideas

I have an idea. Your O2 sensor is bad. Buy a new one. When they are not working like they are supposed to, chances are they crapped out. Long rich and long lean readings usually mean they are bad, especially when your car is idle. If it doesn't fluctuate back and forth repeatedly, it's toast. Just purchase a new one.

It'll save you a lot of headaches.
Kevin Thomas is offline   Reply With Quote
Old 11-11-2001, 02:10 AM   #3
Niloc
Scooby Newbie
 
Member#: 3296
Join Date: Dec 2000
Location: The Hamptons NY usa
Vehicle:
99 impreza RS
Blue

Default

all ready did that. also tried it in another RS, it works. Also tried bypassing the whirring harness, no change.
Niloc is offline   Reply With Quote
Old 11-11-2001, 10:33 AM   #4
yamarocket630
Scooby Specialist
 
Member#: 9436
Join Date: Aug 2001
Chapter/Region: MWSOC
Location: My member# is lower than yours
Vehicle:
05 Saab 9-5 Aero

Default

If both your factory O2 sensor and the a/f sensor are reading lean, and the car is running rich, then the sensors are both bad (unlikely) or they are not reading the actual exhuast content due to a leak upstream pulling air into the exhuast and leaning the exhuast out before it gets to the sensors.
yamarocket630 is offline   Reply With Quote
Old 11-11-2001, 11:48 AM   #5
Niloc
Scooby Newbie
 
Member#: 3296
Join Date: Dec 2000
Location: The Hamptons NY usa
Vehicle:
99 impreza RS
Blue

Default

That's a thought, Ill check it out. Any more ideas
Niloc is offline   Reply With Quote
Old 11-11-2001, 10:36 PM   #6
Niloc
Scooby Newbie
 
Member#: 3296
Join Date: Dec 2000
Location: The Hamptons NY usa
Vehicle:
99 impreza RS
Blue

Default

bump
Niloc is offline   Reply With Quote
Old 11-11-2001, 11:04 PM   #7
HndaTch627
Scooby Guru
 
Member#: 6551
Join Date: May 2001
Chapter/Region: MWSOC
Location: Carol Stream, IL
Vehicle:
'01 GC8 Dinged STM
'09 Concours 14 ABS Black

Default

well if you O2 was bad you'd have a MIL set...check your connection, sounds like your connection is bad to me, like corrosion has built up.

jeremy
HndaTch627 is offline   Reply With Quote
Old 11-11-2001, 11:30 PM   #8
Niloc
Scooby Newbie
 
Member#: 3296
Join Date: Dec 2000
Location: The Hamptons NY usa
Vehicle:
99 impreza RS
Blue

Default

tryed bypassing the harness, it's not the whirring.
Niloc is offline   Reply With Quote
Old 11-14-2001, 01:05 AM   #9
Niloc
Scooby Newbie
 
Member#: 3296
Join Date: Dec 2000
Location: The Hamptons NY usa
Vehicle:
99 impreza RS
Blue

Default

Bump
Niloc is offline   Reply With Quote
Old 11-14-2001, 07:55 AM   #10
wac
Scooby Specialist
 
Member#: 689
Join Date: Dec 1999
Chapter/Region: NESIC
Location: Lebanon, NH, USA
Vehicle:
2005 Outback 2.5 XT
Champagne Gold Opal

Question

Quote:
all ready did that. also tried it in another RS, it works. Also tried bypassing the whirring harness, no change.
Already did what? Try a new O2 sensor? Or did you swap in a sensor from another car? You just said that your O2 sensor "works" in another car. Does another car's sensor work in yours?

Did you or will you consider swapping both O2 sensors with another car, or replacing both O2 sensors? At the very least, you should try swapping the rear O2 sensor by itself first. That might do something.

How did you bypass the wiring harness? Did you make up a new set of wires that ran directly from the O2 sensor to the ECU? Which wires and/or connectors were "bypassed"? I'm asking this because I don't think it's your wiring.

-WaC
Wayne
wac 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
Where to install an o2 sensor blackburn_wrx_2005 Newbies & FAQs 8 03-19-2010 08:06 AM
Can an O2 sensor read only lean? reddevil Engine Management & Tuning 6 01-03-2006 07:28 AM
Replacing an o2 sensor on an '02 OB craigz Normally Aspirated Powertrain 0 07-16-2004 11:53 PM
Anyone want to sell an o2 sensor? miraclemonkeywrx North West Impreza Club Forum -- NWIC 1 10-13-2003 06:20 PM
Will an open DP hurt an o2 sensor Blue02WRX Factory 2.0L Turbo Powertrain 2 04-29-2003 04:26 PM


All times are GMT -4. The time now is 01:29 AM.


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.