SaturnFans.com
saturnfans.com - classifieds - forums


Go Back   SaturnFans.com Forums > Models > Saturn S-Series > S-Series Tech

Reply
 
Thread Tools Display Modes
Old 09-28-2008, 01:02 PM   #1
LTond56
Member
LTond56 is on a distinguished road
 
Join Date: Sep 2008
Posts: 217
Default After cat O2 sensor ?

I know the PCM does not use after cat O2 sensor data to regulate fuel/air but if the heater circuit fails (SES P0141) does that cause it to run in open-loop?
LTond56 is offline   Reply With Quote
SaturnFans.com Sponsored Links
Old 09-28-2008, 01:13 PM   #2
fdryer
Super Member
fdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond reputefdryer has a reputation beyond repute
 
fdryer's Avatar
 
Join Date: Jan 2006
Location: NYC
Posts: 45,649
 

2003 L-Series 3.0L Sedan
Default Re: After cat O2 sensor ?

Simply, no, because of the same correct assumption about the front O2 sensor; the front sensor is used (when its at operating temperature) to regulate the air/fuel mixture in closed loop mode. If this sensor fails then the EFI system will run in open loop mode. The rear sensor is monitoring the catcon output to rat you out to the emission inspector if the catcon goes.
...
VCX NANO
fdryer is offline   Reply With Quote
Old 09-28-2008, 02:38 PM   #3
Low Saturn
Super Member
Low Saturn is a splendid one to beholdLow Saturn is a splendid one to beholdLow Saturn is a splendid one to beholdLow Saturn is a splendid one to beholdLow Saturn is a splendid one to beholdLow Saturn is a splendid one to beholdLow Saturn is a splendid one to beholdLow Saturn is a splendid one to behold
 
Low Saturn's Avatar
 
Join Date: Aug 2003
Location: San Jose, CA
Posts: 15,308
 

2007 AURA XR
2001 SC2
Default Re: After cat O2 sensor ?

The heated oxygen sensor (HO2S) is mounted behind the catalytic converter. This sensor is used to determine the oxygen storage capability of the catalytic converter. Oxygen storage capability is used as a measure of converter condition, and its ability to perform its function. Due to the location of the rear HO2S, it requires additional heat to operate properly. This sensor incorporates a heater (12 ohms), which is controlled ON or OFF by the powertrain control module (PCM). The PCM diagnoses the heater and its related wiring by monitoring electrical current. A DTC P0141 will set if the current range does not fall within the calibrated limits.

Conditions for Setting the DTC:

DTC P0141 will set if the following conditions exist for longer than 50 seconds when the catalyst temperature is less than 775C (1,472F) and:

-The current feedback is less than 0.5 amps OR
-The current feedback is greater than 2.4 amps.

Diagnostic Aids:

Normal scan tool readings in closed loop will show the oxygen sensor voltage varying between 10-999 mV.
...
Mike

-1991 Turbo SL2.
11.809 @ 116.488 mph
www.differentracing.com

-2001 Limited Edition SC2 (#78)
-2001 Chevrolet Suburban
-2007 Saturn Aura XR
-2011 Rally Yellow Chevrolet Camaro 2SS RS
Low Saturn is offline   Reply With Quote
Old 09-28-2008, 03:16 PM   #4
LTond56
Member
LTond56 is on a distinguished road
 
Join Date: Sep 2008
Posts: 217
Default Re: After cat O2 sensor ?

Thanks for the detailed response. Not sure yet what the problem is but the P0141 eventually comes back. If the car is driven right after it is started it never shows up. Sit idling too long from a cold start and it always comes back. Connector and wiring back to sensor are visibly good but connector forward disappears in a black hole above the starter. Wish I had a lift! My condo complex does not appreciate cars on jack-stands either. The heater circuit DTC P0141 is the only one that shows up so can I assume the rest of the sensor and the cat are fine?
LTond56 is offline   Reply With Quote
Reply

Bookmarks


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
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
Bad O2 Sensor or Cat Converter? BobbyBeans S-Series Tech 5 06-27-2009 09:34 AM
fooling oxygen sensor after cat grntdean S-Series Mods 4 04-14-2006 03:36 PM
Code P137 - Cat. O2 Sensor Red97sc2 S-Series Tech 1 02-28-2005 04:24 PM
effects on O2 sensor from removing the cat poiuytrewa Mods and Performance 6 10-01-2004 11:39 AM
rear cat sensor voltage ? sc2dave Miscellaneous Tech 4 08-09-2004 11:18 PM


All times are GMT -4. The time now is 06:15 PM.

Advanced Forum Search | Advanced Photo Search


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2022, vBulletin Solutions Inc.
SaturnFans.com. The Saturn Enthusiasts Site.