BMW M3 Forum (E90 E92)

BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read


Go Back   M3Post - BMW M3 Forum > E90/E92 M3 Technical Topics > Engine, Transmission, Exhaust, Drivetrain, ECU Software Modifications
 
Post Reply
 
Thread Tools Search this Thread
      02-06-2010, 11:18 AM   #1
aus
Major General
United_States
888
Rep
9,031
Posts

Drives: Odysse
Join Date: Jul 2005
Location: Seal Beach, CA

iTrader: (10)

How difficult would it be to extend one set of O2 sensors?

Just wondering how difficult it would be to extend the second set of O2 sensors to behind the secondary cats? Wouldn't it just be splicing a longer wire to the secondary O2 wire?
__________________
Let me get this straight... You are swapping out parts designed by some of the top engineers in the world because some guys sponsored by a company told you it's "better??" But when you ask the same guy about tracking, "oh no, I have a kid now" or "I just detailed my car." or "i just got new tires."
Appreciate 0
      02-06-2010, 12:34 PM   #2
RedGTS
Private
7
Rep
56
Posts

Drives: Multiple
Join Date: Aug 2009
Location: TN

iTrader: (0)

I asked about that the other day and never got much of a response, but I think the answer is yes, you can splice in a comparable gauge wire and extend them. As far as I can tell no one makes a plug and play extender harness like they do for many GM cars, etc. I'm not sure how you would go about routing the extra wire though. Does the heat shielding in the top of the tunnel area come out so the extra wire could be placed behind it rather than between it and the exhaust? If not I'm not sure if the wiring would hold up if it's mounted on the shielding directly above the hot exhaust.

BTW I was interested in this because I have an aftermarket X-pipe with HFC's which has the secondary O2 bungs much farther down the pipe--why would you want to reposition the bungs behind the secondary cats on the factory exhaust--you thinking of cutting out the primaries or something?
Appreciate 0
      02-06-2010, 02:18 PM   #3
RedGTS
Private
7
Rep
56
Posts

Drives: Multiple
Join Date: Aug 2009
Location: TN

iTrader: (0)

Quote:
Originally Posted by PencilGeek View Post
Yes you can extend them with wiring. My primary O2 sensors have extensions on them.
What kind of wire did you use, and is it soldered in or what?
Appreciate 0
      02-06-2010, 03:43 PM   #4
aus
Major General
United_States
888
Rep
9,031
Posts

Drives: Odysse
Join Date: Jul 2005
Location: Seal Beach, CA

iTrader: (10)

Quote:
Originally Posted by RedGTS View Post
I asked about that the other day and never got much of a response, but I think the answer is yes, you can splice in a comparable gauge wire and extend them. As far as I can tell no one makes a plug and play extender harness like they do for many GM cars, etc. I'm not sure how you would go about routing the extra wire though. Does the heat shielding in the top of the tunnel area come out so the extra wire could be placed behind it rather than between it and the exhaust? If not I'm not sure if the wiring would hold up if it's mounted on the shielding directly above the hot exhaust.

BTW I was interested in this because I have an aftermarket X-pipe with HFC's which has the secondary O2 bungs much farther down the pipe--why would you want to reposition the bungs behind the secondary cats on the factory exhaust--you thinking of cutting out the primaries or something?
I'm pretty sure the heat shielding comes out since that's how most install the short shifter.

I was thinking if one could extent the post-cat O2 sensors to behind the secondary cats, you could cut out the primary cats or get an X-pipe with HFC's downstream and not get a check engine light. It seems making a longer O2 sensor cable would be easier than trying to come up with some O2 sim- just not sure why the aftermarket folks haven't done this.

.
__________________
Let me get this straight... You are swapping out parts designed by some of the top engineers in the world because some guys sponsored by a company told you it's "better??" But when you ask the same guy about tracking, "oh no, I have a kid now" or "I just detailed my car." or "i just got new tires."
Appreciate 0
      02-16-2010, 10:01 AM   #5
aus
Major General
United_States
888
Rep
9,031
Posts

Drives: Odysse
Join Date: Jul 2005
Location: Seal Beach, CA

iTrader: (10)

Quote:
Originally Posted by RedGTS View Post
What kind of wire did you use, and is it soldered in or what?
I'd be interested as well since it would allow cutting out the primary cats, keeping the secondary cats and getting no check engine light. The secondary cats seem to be bigger than the primary ones too.
__________________
Let me get this straight... You are swapping out parts designed by some of the top engineers in the world because some guys sponsored by a company told you it's "better??" But when you ask the same guy about tracking, "oh no, I have a kid now" or "I just detailed my car." or "i just got new tires."
Appreciate 0
      02-24-2010, 02:56 AM   #6
aus
Major General
United_States
888
Rep
9,031
Posts

Drives: Odysse
Join Date: Jul 2005
Location: Seal Beach, CA

iTrader: (10)

One more try.
__________________
Let me get this straight... You are swapping out parts designed by some of the top engineers in the world because some guys sponsored by a company told you it's "better??" But when you ask the same guy about tracking, "oh no, I have a kid now" or "I just detailed my car." or "i just got new tires."
Appreciate 0
      02-24-2010, 07:48 AM   #7
Radiation Joe
Veni Vidi Vici
Radiation Joe's Avatar
United_States
89
Rep
2,750
Posts

Drives: '11 JB/BBe-6sp-e90
Join Date: Jul 2008
Location: Macungie PA

iTrader: (0)

Garage List
2011 e90 M3-Sold  [8.50]
2003 RS6 - Sold  [0.00]
2009 e90 M3 - Gone  [0.00]
2003 M3 SOLD  [0.00]
old 2002  [10.00]
You have to solder the wires. This was pretty common on e46 M3s when installing the European header and mid section.
Appreciate 0
      02-24-2010, 10:08 AM   #8
Green-Eggs
BimmerPost Supporting Vendor
United_States
1431
Rep
1,612
Posts


Drives: BMW
Join Date: Jul 2007
Location: Los Angeles

iTrader: (3)

Make sure to use the correct gauge wires

-Sam
Appreciate 0
      02-24-2010, 10:35 AM   #9
Kyoshi71
Colonel
Kyoshi71's Avatar
93
Rep
2,528
Posts

Drives: 2010 M3 Coupe
Join Date: Jul 2006
Location: New York

iTrader: (0)

Ohms need to match
Appreciate 0
      02-24-2010, 12:14 PM   #10
2010e92m3
Banned
0
Rep
30
Posts

Drives: 2010 E92 M3 Sedan
Join Date: Feb 2010
Location: Kansas

iTrader: (0)

Unfortunately soldering is the only option for now. Anyone seen any aftermarket plugin style extensions?
Appreciate 0
      02-24-2010, 12:35 PM   #11
Lemans_Blue_M
Automotive Industry Insider
Lemans_Blue_M's Avatar
United_States
462
Rep
1,948
Posts

Drives: Lemans Blue M3
Join Date: Aug 2007
Location: Texas

iTrader: (0)

Quote:
Originally Posted by Kyoshi71 View Post
Ohms need to match
+1

This is a must...

The resistance of the wire extension needs to match the original OE 02 sensor wires, in order to ensure a proper signal feedback from the sensors to the ECU.

The 02 sensors work off very sensitive differential voltage values (to calculate the oxygen content in your exhaust gas stream), so a very high, or very low resistance wire will skew the signal feedback results.

When that happens, the ECU will detect an issue (and throw a fault code)...when there is actually nothing wrong.

A poorly executed solder joint (between the OE O2 sensor wire and the new wire extension) will also be problematic.

You will end up chasing a 'phantom' 02 sensor fault code that doesn't exist.
__________________
The best is yet to come...
Appreciate 0
      02-24-2010, 12:54 PM   #12
aus
Major General
United_States
888
Rep
9,031
Posts

Drives: Odysse
Join Date: Jul 2005
Location: Seal Beach, CA

iTrader: (10)

Thanks guys. I figured it was a little more involved than just splicing wires together.
So it's not possible to male a plug and play type connection?

Also, would you need to move both sensors or just the second, post cat sensor of one were to place it after the secondary cats?
__________________
Let me get this straight... You are swapping out parts designed by some of the top engineers in the world because some guys sponsored by a company told you it's "better??" But when you ask the same guy about tracking, "oh no, I have a kid now" or "I just detailed my car." or "i just got new tires."
Appreciate 0
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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



All times are GMT -5. The time now is 01:15 PM.




m3post
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST