Getting the right O2 sensors in Bosch for a lot fewer $; plus W12 #'s
05-12-2014, 12:39 AM
#1
AudiWorld Super User
Thread Starter
Getting the right O2 sensors in Bosch for a lot fewer $; plus W12 #'s
From having been through running down 02 sensors for the W12, a simple tip to save a bunch of $. You can buy them from Audi at $271 list/$202 discounted, or you can buy the Bosch sensors for about $80 on Amazon. Bosch is the OES on the sensors, and each of the ones I have pulled has an Audi number but also a Bosch number.
The trouble buying the Bosch ones, at least for the W12, is finding accurate part # information. Essentially EVERY listing I have seen for the W12 is wrong, and on all the web sites. If you buy them relying on those listings, they seem kind of generic--always with black connectors even if some of the OE ones are brown, and often long connecting cables for the given position. The ones you get will work as long as they are wide band, heated with 6 pin connectors (one of which is blank as far as a wire), but variously the connecting cords will be somewhat to way too long (lots of zip ties, which even come in the box...) and or for one of the two banks on each side (for a W12 and probably an S8) the connectors will be black instead of the OE brown. One bank is OE black and one brown on each side to avoid getting the connectors mixed up.
Well, the "fix" is easy. If you pull your old OE sensor, it has a very long Bosch number included on it. For example, 0 258 007 258/259 for the B1 S2 sensor on the 2006 W12 (passenger side, rear one of the two). Well, to get the accurate Bosch number using their simplified 5 digit numbering for their aftermarket parts, just start with "17" and then take the last three digits right BEFORE the slash (/) mark. Thus, that same sensor is Bosch 17258. And for what its worth, the front sensor on the right side on the W12 (at least in 2006) is 0 258 007 177/178. That becomes 17177. And indeed in both cases after earlier getting shipped sensors with too long of cords and the rear sensor with a black connector instead of OE brown, once I mimic'ed the Bosch number by deciphering how they got to the five digits for the ones on Amazon or elsewhere, presto it all came out right.
In a separate post, I have confirmed all of the W12 pre cat sensors can be pulled, and fairly easily with simple tools. In particular, a 7/8" crowfoot wrench in 3/8" drive (½" drive will be hard to fit in the available space, plus a one foot long 3/8" socket drive extension on the bottom with the crowfoot attached to it, and one more on top of that until your ratchet drive. The post cat ones are a likely nightmare. But the "pull engine" typical warnings on standard forward W12 sensors are all ill informed, from having done the job on both of the passenger side sensors. The driver's side set up is essentially identical, other than the connecting cords go all the way around the back of the motor over to the passenger side air box area where all the W12 O2 sensor connectors are grouped.
The trouble buying the Bosch ones, at least for the W12, is finding accurate part # information. Essentially EVERY listing I have seen for the W12 is wrong, and on all the web sites. If you buy them relying on those listings, they seem kind of generic--always with black connectors even if some of the OE ones are brown, and often long connecting cables for the given position. The ones you get will work as long as they are wide band, heated with 6 pin connectors (one of which is blank as far as a wire), but variously the connecting cords will be somewhat to way too long (lots of zip ties, which even come in the box...) and or for one of the two banks on each side (for a W12 and probably an S8) the connectors will be black instead of the OE brown. One bank is OE black and one brown on each side to avoid getting the connectors mixed up.
Well, the "fix" is easy. If you pull your old OE sensor, it has a very long Bosch number included on it. For example, 0 258 007 258/259 for the B1 S2 sensor on the 2006 W12 (passenger side, rear one of the two). Well, to get the accurate Bosch number using their simplified 5 digit numbering for their aftermarket parts, just start with "17" and then take the last three digits right BEFORE the slash (/) mark. Thus, that same sensor is Bosch 17258. And for what its worth, the front sensor on the right side on the W12 (at least in 2006) is 0 258 007 177/178. That becomes 17177. And indeed in both cases after earlier getting shipped sensors with too long of cords and the rear sensor with a black connector instead of OE brown, once I mimic'ed the Bosch number by deciphering how they got to the five digits for the ones on Amazon or elsewhere, presto it all came out right.
In a separate post, I have confirmed all of the W12 pre cat sensors can be pulled, and fairly easily with simple tools. In particular, a 7/8" crowfoot wrench in 3/8" drive (½" drive will be hard to fit in the available space, plus a one foot long 3/8" socket drive extension on the bottom with the crowfoot attached to it, and one more on top of that until your ratchet drive. The post cat ones are a likely nightmare. But the "pull engine" typical warnings on standard forward W12 sensors are all ill informed, from having done the job on both of the passenger side sensors. The driver's side set up is essentially identical, other than the connecting cords go all the way around the back of the motor over to the passenger side air box area where all the W12 O2 sensor connectors are grouped.
Last edited by MP4.2+6.0; 05-12-2014 at 11:51 AM.
05-19-2014, 10:07 AM
#2
AudiWorld Member
Join Date: Oct 2002
Location: Connecticut, USA
Posts: 560
Likes: 0
Received 0 Likes
on
0 Posts
Looking at this write-up I may try this to save a few $$. I have done similar with aftermarket bosch that did not include the pigtail (correct harness).
Do these typically come with butt crimp/ heatshrink tubing to utilize the original harness? In some cases would it even be worth reusing the original harness? I have a b2s2 going on me and need to address it soon.
Do these typically come with butt crimp/ heatshrink tubing to utilize the original harness? In some cases would it even be worth reusing the original harness? I have a b2s2 going on me and need to address it soon.
05-19-2014, 11:20 AM
#3
AudiWorld Super User
Thread Starter
It is just plug and play...
Since probably the mid 80's (as in my old 5000S), quality sensors are typically plug and play. On my old 5000S you could get Bosch in the DIY with no plug end, but long since gone AFAIK. You just unplug the O2 sensor at the connection block (on a W12 they are all at the passenger side air box area; on an S8 I think they may be in a few places) and plug the new one in. No splicing, heat shrink, etc. required as long as you don't have any harness damage on the "car" side of that final connection point. If you have a W12 of my similar vintage, even the cable lengths and connector colors should come out the same as OE. Presumably similarly on an S8 if you have time to pull the relevant one to get a number off of it; or maybe take a best guess using on line info and order from Amazon in advance w/ an easy return deal if it isn't the exact fit one and it matters somehow.
But...if you really mean an "S2" sensor, that is one of those more nightmarish post cat sensors, B1 through 4, S1 are all the pre-cat sensors on a W12 or S8. If I remember right though, PaulW tackled an S2 located sensor on his S8; IIRC he may have pulled a down pipe.
But...if you really mean an "S2" sensor, that is one of those more nightmarish post cat sensors, B1 through 4, S1 are all the pre-cat sensors on a W12 or S8. If I remember right though, PaulW tackled an S2 located sensor on his S8; IIRC he may have pulled a down pipe.
Last edited by MP4.2+6.0; 05-19-2014 at 09:24 PM.
05-19-2014, 06:08 PM
#4
AudiWorld Member
Join Date: Oct 2002
Location: Connecticut, USA
Posts: 560
Likes: 0
Received 0 Likes
on
0 Posts
Whoops my error. B2S1. Looks accesable from under the car. I'm due for an oil change again soon so I'll hit it all at once. I may get under prior to give it a good look over and see where the harness runs to. I know I need a bentley and updated version of ETKA. I haven't been able to find a good Audi version of ETKA on the torrent sites.
For the longest time all I have had is mid 80's-early 90's Volkswagens, hence my original question. Probably the same sensors that were in your 5000.
Thanks!
For the longest time all I have had is mid 80's-early 90's Volkswagens, hence my original question. Probably the same sensors that were in your 5000.
Thanks!
05-20-2014, 05:53 AM
#6
AudiWorld Senior Member
Join Date: Oct 2003
Posts: 1,209
Likes: 0
Received 0 Likes
on
0 Posts
Not sure if this is applicable, but on my B6 S4 the wideband bosch o2 sensors sold at advance auto were completely plug and play, down the connector. It looks like the wideband ones are standardized, as far as i can tell.
05-20-2014, 07:13 AM
#7
AudiWorld Super User
Thread Starter
Yes, standard AFAIK on the sensor; the cord varies
They are five conductor sideband sensors with a six connector connector. But what still varies is the cord length, and sometimes the connector end color for color coding.
Two of the four connectors on a W12 for the pre cat forward sensors ("S1'"s) for example are brown. The shortest factory connector is about 9 inches and the longest maybe close to 5 feet long. I could use the 5 foot one in any position I suppose, but that could be a bunch of zip ties! While fairly generic, seriously mismatched cord lengths is a give away of aftermarket; would raise questions for me if I saw that on a used one. Anyway, with the right Bosch # in hand, you can get the correct length and end connector cold scheme for the same much lower $ OES than dealer/Audi branded.
Two of the four connectors on a W12 for the pre cat forward sensors ("S1'"s) for example are brown. The shortest factory connector is about 9 inches and the longest maybe close to 5 feet long. I could use the 5 foot one in any position I suppose, but that could be a bunch of zip ties! While fairly generic, seriously mismatched cord lengths is a give away of aftermarket; would raise questions for me if I saw that on a used one. Anyway, with the right Bosch # in hand, you can get the correct length and end connector cold scheme for the same much lower $ OES than dealer/Audi branded.
Last edited by MP4.2+6.0; 05-20-2014 at 07:16 AM.
Trending Topics
05-20-2014, 08:51 AM
#8
AudiWorld Member
Join Date: Oct 2002
Location: Connecticut, USA
Posts: 560
Likes: 0
Received 0 Likes
on
0 Posts
Mp4.2+6.0
I used the places you sent me in the pm. Thank you for the input. Still a bit confusing as to finding the correct part/bosch number. I came across this picture which I am sure came from ETKA or Erwin which actually shows the breakdown of the exhaust manifolds and 02 sensors. However it still does not provide the correct number. It looks like I'll be getting into this sooner than expected.
I used the places you sent me in the pm. Thank you for the input. Still a bit confusing as to finding the correct part/bosch number. I came across this picture which I am sure came from ETKA or Erwin which actually shows the breakdown of the exhaust manifolds and 02 sensors. However it still does not provide the correct number. It looks like I'll be getting into this sooner than expected.
05-20-2014, 11:32 AM
#9
AudiWorld Super User
Thread Starter
Try here:
http://www.boschautoparts.com/Vehicl...artFinder.aspx
I get Bosch 17182 as the rear position S1 sensors on either side.
I got the same # when I typed in a 2009 S8 onto the Rock Auto parts finder once you drill down to the O2 sensors. http://www.rockauto.com At $86.79, a better price than Amazon in this case.
When you pull your existing sensor, look for "182" or maybe 182/followed by some other number like "182/183" at the end of the long Bosch part number to confirm it is the exact one. From my experience w/ the Bosch catalog, it may not be, though apparently the W12 sensor cord lengths changed some over time. If not and you care about cord lengths or mismatch connector end issues, you could then track down the exact one from the # you find on you existing sensor.
I get Bosch 17182 as the rear position S1 sensors on either side.
I got the same # when I typed in a 2009 S8 onto the Rock Auto parts finder once you drill down to the O2 sensors. http://www.rockauto.com At $86.79, a better price than Amazon in this case.
When you pull your existing sensor, look for "182" or maybe 182/followed by some other number like "182/183" at the end of the long Bosch part number to confirm it is the exact one. From my experience w/ the Bosch catalog, it may not be, though apparently the W12 sensor cord lengths changed some over time. If not and you care about cord lengths or mismatch connector end issues, you could then track down the exact one from the # you find on you existing sensor.
