RX8Club.com
Register Photo Gallery FAQ Members List Calendar Search Today's Posts Mark Forums Read Used CarsRX8 Live!Vendors TSB & Recalls

Go Back   RX8Club.com > General Topics > RX-8 Discussion
Sign in using an external account
Register Forgot Password?

Welcome to RX8Club.com!
Welcome to RX8Club.com,

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, at no cost, you will have access to start new topics, reply to conversations, privately message other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join RX8Club.com today!


Reply
 
 
 
 
LinkBack Thread Tools Search this Thread Rate Thread Display Modes
Old 06-15-2012, 11:17 AM   #1
Registered User
 
Trader Score: (0)
Join Date: Feb 2012
Posts: 69
Confused about rear 02 sensor

I was looking at my old Catalytic yesterday, and i noticed that the bung for the 02 sensor seems to be before the cat does anything to the exhaust gases. If you look through the cat-side where the exhaust would flow into, you can clearly see the 02 just stuck in there before any screens or anything. How does the sensor measure if the cat is doing its job? Does it measure temperature; and a clog, or anything under optimum flow would cause raise in temp?
This ad is not displayed to registered and logged-in members.
Register your free account today and become a member on RX8Club.com!

Last edited by 06blackAT; 06-15-2012 at 11:55 AM.
06blackAT is offline   Reply With Quote
Old 06-15-2012, 02:18 PM   #2
Go Red Wings!
 
Wingznut's Avatar
 
Trader Score: (0)
Join Date: May 2010
Location: Portland, OR
Posts: 782
john.rembecki Wingznut
There are two O2 sensors... The front (before the cat) measures the oxygen in the exhaust and sends the information to the ECU (along with many other inputs) to determine fuel trim. The ECU compares the front and rear O2 sensors (after the cat) to determine the catalytic converter's performance. If they are too similar, the cat is not doing it's job.
__________________
2005 Mazda RX8 Shinka 6MT

Wingznut is offline   Reply With Quote
Old 06-15-2012, 02:25 PM   #3
Extraordinary Engineering
 
DarkBrew's Avatar
 
Trader Score: (0)
Join Date: Oct 2005
Location: Burls On
Posts: 4,652
Send a message via Skype™ to DarkBrew
Are you asking why the sensor is part way into the cat rather than after it?

Read this post
http://www.rx8club.com/showpost.php?...7&postcount=10
__________________
??
2004 SS GT 6MT : Clear corners : AFE SS : Voodoo : leather boot : KDW2 : RB Rev8, screens : Al strakes : Catch can : Clutch pedal reinforcement : RB springs, sway bars and end links : D-specs : Racing Brake rotors and SS lines : Hawk Ceramics : AP WCS tune : MM OP mod : RB gauges & Ram Air : N3Z1-18-400 : GROM + Sirius : BHR ignition : Davesport Cat : Waiting : Sohn adapter
DarkBrew is offline   Reply With Quote
Old 06-15-2012, 09:08 PM   #4
Registered User
 
Trader Score: (0)
Join Date: Feb 2012
Posts: 69
is the sensor that is part way into the cat the rear one? I'm asking this because if there is supposed to be 2 "filters" in the cat ( the sensor sitting between them) then mine appears to be missing the front one... i can see the sensor while looking into the cat...
06blackAT is offline   Reply With Quote
Old 06-15-2012, 09:10 PM   #5
Verbose Moderator
 
RIWWP's Avatar
 
Trader Score: (2)
Join Date: Oct 2007
Location: PA Poconos, NYC
Posts: 9,351
Send a message via AIM to RIWWP
The front O2 sensor is in the manifold.

The rear O2 sensor is in the middle of the cat between the 2 cat elements.

If you can look in the front of your cat and see the sensor tip, then you are missing your front cat element.
__________________
Are you a new owner, or looking to buy an RX-8? New and Potential Owners START HERE!
Do you have a question that you want to ask and don't want to get flamed for asking? Dumb Question Thread - no flaming or sarcasm allowed
New to the RX-8 and interested in basic information about modding it? Newbie's Guide to Modding the RX-8 (First 11 posts)
A FLASHING CEL IS ALWAYS A MISFIRE!!! Suffering From a Misfire? START HERE
RIWWP is offline   Reply With Quote
Old 06-15-2012, 09:15 PM   #6
Registered User
 
Trader Score: (0)
Join Date: Feb 2012
Posts: 69
alright, and i bought it like that from the dealer.... are they entitled to replace it.. they sold me a car that should not have passed inspection. It was a mazda dealership btw, the same dealership that replaced the engine. They should have noticed.

Last edited by 06blackAT; 06-15-2012 at 09:19 PM.
06blackAT is offline   Reply With Quote
Old 06-15-2012, 09:18 PM   #7
Extraordinary Engineering
 
DarkBrew's Avatar
 
Trader Score: (0)
Join Date: Oct 2005
Location: Burls On
Posts: 4,652
Send a message via Skype™ to DarkBrew
So do you see any elements at all or is it a gutted cat?

What area do you live in?
__________________
??
2004 SS GT 6MT : Clear corners : AFE SS : Voodoo : leather boot : KDW2 : RB Rev8, screens : Al strakes : Catch can : Clutch pedal reinforcement : RB springs, sway bars and end links : D-specs : Racing Brake rotors and SS lines : Hawk Ceramics : AP WCS tune : MM OP mod : RB gauges & Ram Air : N3Z1-18-400 : GROM + Sirius : BHR ignition : Davesport Cat : Waiting : Sohn adapter
DarkBrew is offline   Reply With Quote
Old 06-15-2012, 09:18 PM   #8
Verbose Moderator
 
RIWWP's Avatar
 
Trader Score: (2)
Join Date: Oct 2007
Location: PA Poconos, NYC
Posts: 9,351
Send a message via AIM to RIWWP
Depends on the liability / warranty that the car was purchased under, and state law. If they didn't actually put anything in writing and the state doesn't have any laws to protect you in that regard then you are out of luck. If the state has laws to protect you or there was some level of warranty, then yes, you have some recourse.

Depending on the mileage and year, there is also a mandatory federal law (US) covering the cat (among some other emissions stuff) for 8yrs 80,000 miles.
__________________
Are you a new owner, or looking to buy an RX-8? New and Potential Owners START HERE!
Do you have a question that you want to ask and don't want to get flamed for asking? Dumb Question Thread - no flaming or sarcasm allowed
New to the RX-8 and interested in basic information about modding it? Newbie's Guide to Modding the RX-8 (First 11 posts)
A FLASHING CEL IS ALWAYS A MISFIRE!!! Suffering From a Misfire? START HERE
RIWWP is offline   Reply With Quote
Old 06-15-2012, 09:27 PM   #9
Registered User
 
Trader Score: (0)
Join Date: Feb 2012
Posts: 69
i have 82xxx miles. Its not a problem if i can't get a new cat i was just looking to make a few hundred dollars. I already have a midpipe i'm satisfied wit, i would most likley end up selling the new cat or keeping it around for inspection. I just think it kind of sucks. The fact that a mazda dealership would sell a customer a car that would inevidably end up costing over a thousand dollars. Also the fact that the car should have never left the lot because it should not have passed inspection.
06blackAT is offline   Reply With Quote
Old 06-15-2012, 09:27 PM   #10
Registered User
 
Trader Score: (0)
Join Date: Feb 2012
Posts: 69
Oh and i live in mass
06blackAT is offline   Reply With Quote
Old 06-15-2012, 09:31 PM   #11
Registered User
 
Trader Score: (0)
Join Date: Feb 2012
Posts: 69
If the car wasn't so e'ffin fun to drive i would have done away with it already. Within 2 months, its needed a new cat, new front breaks and rotors, new tires, and over 60" of oil lines.
06blackAT is offline   Reply With Quote
Old 06-15-2012, 09:46 PM   #12
Verbose Moderator
 
RIWWP's Avatar
 
Trader Score: (2)
Join Date: Oct 2007
Location: PA Poconos, NYC
Posts: 9,351
Send a message via AIM to RIWWP
Take a peek at this then. http://www.mass.gov/ocabr/consumer/a...ranty-law.html

Should have a 30-day warranty by law, and at 2 months you are past that. But some other items might be reimbursable.

And if you didn't get an actual wearranty document from the dealer, then note this section:
Quote:
Dealer Fails to Provide Correct Warranty: If the dealer does not give you a warranty or gives you one that is incomplete or inaccurate, you are still entitled to warranty repairs. Your warranty, however, will not begin to expire until the dealer gives you a complete, accurate copy of the warranty.
__________________
Are you a new owner, or looking to buy an RX-8? New and Potential Owners START HERE!
Do you have a question that you want to ask and don't want to get flamed for asking? Dumb Question Thread - no flaming or sarcasm allowed
New to the RX-8 and interested in basic information about modding it? Newbie's Guide to Modding the RX-8 (First 11 posts)
A FLASHING CEL IS ALWAYS A MISFIRE!!! Suffering From a Misfire? START HERE
RIWWP is offline   Reply With Quote
Old 06-15-2012, 09:48 PM   #13
Go Red Wings!
 
Wingznut's Avatar
 
Trader Score: (0)
Join Date: May 2010
Location: Portland, OR
Posts: 782
john.rembecki Wingznut
Quote:
Originally Posted by 06blackAT View Post
If the car wasn't so e'ffin fun to drive i would have done away with it already. Within 2 months, its needed a new cat, new front breaks and rotors, new tires, and over 60" of oil lines.
Well, to be fair... All that didn't fail due to 2 months of use. You bought a six year old car with 82k on it. Brakes/rotors, tires, and a cat are not unusual for any car of that age/miles.

I presume you did a full inspection of the car and knew what you were in for before buying it?
__________________
2005 Mazda RX8 Shinka 6MT

Wingznut is offline   Reply With Quote
Old 06-15-2012, 09:49 PM   #14
Verbose Moderator
 
RIWWP's Avatar
 
Trader Score: (2)
Join Date: Oct 2007
Location: PA Poconos, NYC
Posts: 9,351
Send a message via AIM to RIWWP
Agreed, he needed to research and inspect better. But he still has legal rights in his state that cover him against those same items. Though may be out of luck for not researching his legal rights either.
__________________
Are you a new owner, or looking to buy an RX-8? New and Potential Owners START HERE!
Do you have a question that you want to ask and don't want to get flamed for asking? Dumb Question Thread - no flaming or sarcasm allowed
New to the RX-8 and interested in basic information about modding it? Newbie's Guide to Modding the RX-8 (First 11 posts)
A FLASHING CEL IS ALWAYS A MISFIRE!!! Suffering From a Misfire? START HERE
RIWWP is offline   Reply With Quote
Old 06-15-2012, 11:01 PM   #15
Registered User
 
Trader Score: (0)
Join Date: Feb 2012
Posts: 69
I am fully aware of the 30 day state protection, I was fully aware that this (or any car) is NOT cheap to maintain, I am fully aware that s*&t happens, I did hours of lurking (on this site), I researched my options, and i fell in love with the car. I am capable of maintenance as well as diagnosing and fixing problems (to an extent). However... I am PISSED that the front element of my catalytic converter is missing... for reasons unknown. I bought specifically from a dealer so maybe i would be able to avoid nonsense such as this. The "to be fair" bs is just that... Buying directly from mazda i did not expect to have such problems as half of my cat being missing in action, or oil lines that were so rusted out that they have become porouse like a sponge... and leaked all over my new driveway. I will not be "fair" to a dealership that sold the car in the condition that it was in. The same dealership that wanted 750 dollars to fix oil lines 2 weeks after my "30 day" state protection has expired. I do not appreciate the condescending manner in which you replied about me. You made assumptions that i did not do my "research" and that i am just another sorry member using the forum as some sort of complaint office.
06blackAT is offline   Reply With Quote
Old 06-16-2012, 06:56 AM   #16
Verbose Moderator
 
RIWWP's Avatar
 
Trader Score: (2)
Join Date: Oct 2007
Location: PA Poconos, NYC
Posts: 9,351
Send a message via AIM to RIWWP
Quote:
Originally Posted by 06blackAT View Post
You made assumptions that i did not do my "research" and that i am just another sorry member using the forum as some sort of complaint office.
In general, yes, we did. Reading over your posts there is nothing there to contradict that perception.

Sounds like you have it in hand though.
__________________
Are you a new owner, or looking to buy an RX-8? New and Potential Owners START HERE!
Do you have a question that you want to ask and don't want to get flamed for asking? Dumb Question Thread - no flaming or sarcasm allowed
New to the RX-8 and interested in basic information about modding it? Newbie's Guide to Modding the RX-8 (First 11 posts)
A FLASHING CEL IS ALWAYS A MISFIRE!!! Suffering From a Misfire? START HERE
RIWWP is offline   Reply With Quote
Old 06-16-2012, 03:49 PM   #17
Moderator Noir
 
alnielsen's Avatar
 
Trader Score: (4)
Join Date: Aug 2004
Location: Buddhist Monastery, High Himalaya Mtns. of Tibet
Posts: 11,619
allen.nielsen.908
Send a message via Skype™ to alnielsen
Posts Have Been Removed: Argumentative and Silly Name Calling.
__________________
Don't try this at home. It could be dangerous. I have years of experience.

Emissions and fuel economy haven't exactly been areas of strength for past rotary power plants, but absolutely no one with a soul has ever cared.
- Autoweek

Rotary History:1982 RX7 GS, 1985 RX7 GSL-SE, 2004 RX8 Sport-Continuous Rotary Owner since 1985
Racing History:SCCA Solo II 1979-1986, Skip Barber Comp School 1983, SCCA Club Racing 1987-1993, 2004-2011 Track Days
alnielsen is offline   Reply With Quote
Old 06-16-2012, 05:43 PM   #18
Verbose Moderator
 
RIWWP's Avatar
 
Trader Score: (2)
Join Date: Oct 2007
Location: PA Poconos, NYC
Posts: 9,351
Send a message via AIM to RIWWP
I lost a post from mobile before, but blackAT, we aren't flaming you for getting angry, or even getting screwed. We are simply acknowledging that you could have detected most of the issues (everything but the cat) prior to purchase, but didn't, and the only issue that you couldn't have been reasonably expected to find, you previously said that it didn't matter because you were ditching the cat anyway. Since you could have detected these issues (and didn't investigate thoroughly), and didn't exercise your legal rights within the legal time-span, we aren't really feeling sympathy toward you.

Doesn't mean that we agree with or feel friendly toward the dealer either, since they clearly screwed you. Mostly just a shrug and hope that you learned something from this.
__________________
Are you a new owner, or looking to buy an RX-8? New and Potential Owners START HERE!
Do you have a question that you want to ask and don't want to get flamed for asking? Dumb Question Thread - no flaming or sarcasm allowed
New to the RX-8 and interested in basic information about modding it? Newbie's Guide to Modding the RX-8 (First 11 posts)
A FLASHING CEL IS ALWAYS A MISFIRE!!! Suffering From a Misfire? START HERE
RIWWP is offline   Reply With Quote
Old 06-16-2012, 06:39 PM   #19
Go Red Wings!
 
Wingznut's Avatar
 
Trader Score: (0)
Join Date: May 2010
Location: Portland, OR
Posts: 782
john.rembecki Wingznut
I wasn't being condescending in the least. I wasn't defending the dealership, nor was I accusing you of anything. (Unless in fact, you did buy a car with worn out brakes and tires, and didn't do your due diligence to make yourself aware of such things before purchase. And if that's the case, it's less of an accusation and more of a hope that it's a learning experience for you and anyone else reading this thread.)

I simply pointed out, that the issues I listed (brakes, tires, and cat) are typical for ANY car of that age and use. With your comment that I quoted above, you seemed to be blaming the car for having worn brakes and tires.

As for the cat, I will defend the dealership on this. As an auto mechanic of 10+ years, I can say with all assurance, that no shop or seller would know that the cat was bad, if it didn't have any signs short of disassembling it.
__________________
2005 Mazda RX8 Shinka 6MT

Wingznut is offline   Reply With Quote
Old 06-16-2012, 06:57 PM   #20
wcs
no agenda
 
wcs's Avatar
 
Trader Score: (2)
Join Date: Feb 2005
Location: Ontario
Posts: 4,302
Quote:
Originally Posted by Wingznut View Post
I wasn't being condescending in the least. I wasn't defending the dealership, nor was I accusing you of anything. (Unless in fact, you did buy a car with worn out brakes and tires, and didn't do your due diligence to make yourself aware of such things before purchase. And if that's the case, it's less of an accusation and more of a hope that it's a learning experience for you and anyone else reading this thread.)

I simply pointed out, that the issues I listed (brakes, tires, and cat) are typical for ANY car of that age and use. With your comment that I quoted above, you seemed to be blaming the car for having worn brakes and tires.

As for the cat, I will defend the dealership on this. As an auto mechanic of 10+ years, I can say with all assurance, that no shop or seller would know that the cat was bad, if it didn't have any signs short of disassembling it.
I wish you had have posted earlier
__________________

Those who would trade in their freedom for their protection deserve neither
wcs is online now   Reply With Quote
Old 06-16-2012, 07:04 PM   #21
Extraordinary Engineering
 
DarkBrew's Avatar
 
Trader Score: (0)
Join Date: Oct 2005
Location: Burls On
Posts: 4,652
Send a message via Skype™ to DarkBrew
Quote:
Originally Posted by wcs View Post
I wish you had have posted earlier
You missed my awesome defence of your character
__________________
??
2004 SS GT 6MT : Clear corners : AFE SS : Voodoo : leather boot : KDW2 : RB Rev8, screens : Al strakes : Catch can : Clutch pedal reinforcement : RB springs, sway bars and end links : D-specs : Racing Brake rotors and SS lines : Hawk Ceramics : AP WCS tune : MM OP mod : RB gauges & Ram Air : N3Z1-18-400 : GROM + Sirius : BHR ignition : Davesport Cat : Waiting : Sohn adapter
DarkBrew is offline   Reply With Quote
Old 06-16-2012, 07:04 PM
RX8Club
Mazda RX8




Paid Advertisement


 
 
 
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

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
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -5. The time now is 09:50 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2013, vBulletin Solutions, Inc.
SEO by vBSEO ©2010, Crawlability, Inc.
All content Copyright © 2007 by Internet Brands, Inc.
Emails Backup