View Full Version : O2 sensors (post cats) Where to buy them & OEM or other
cruzanrs6
October 20th, 2011, 01:31
Found out I need to replace both left and right post cat 02 sensors. Audi wants $190 a piece. Are there other options ?
TIA - Scott
JSRS6
October 20th, 2011, 01:37
Yeah, plug those part numbers from the dealer into genuine or ecs. Or you can get a couple of Bosch splice kits from autozone.
Elevens
October 20th, 2011, 04:18
Google these part #'s. Usually Amazon gives the best price.
Audi Part #'s
078906265N Post Right
078906265P Post Left
Bosch Part #'s
Bosch 16067 Post Right
Bosch 16069 Post Left
kismetcapitan
October 20th, 2011, 11:00
what's the purpose of the four post-cat O2 sensors? Is it for closed-loop highway running? For those who have deleted these cats (and sensors), are there problems in highway cruising, either in consistent throttle response, or just crappy gas mileage?
4everRS
October 20th, 2011, 13:11
There are only 2 post cat O2's. One one each side. They are after the precats but before the main cats.
What I've been told is that they are purely for emmissions.
hahnmgh63
October 20th, 2011, 14:09
Cheapest place I found at the time for the Bosch pieces.
http://www.autohausaz.com/audi-auto-parts/index.html
Jimmy
October 20th, 2011, 21:36
Give www.parts.com (http://www.parts.com) a try too...they , for us Benz owners at least , are one of the cheapest and are able to even source and deliver on euro-only parts.
AutohausAZ is also a thumbs up for good prices.
kismetcapitan
October 20th, 2011, 22:26
There are only 2 post cat O2's. One one each side. They are after the precats but before the main cats.
What I've been told is that they are purely for emmissions.
yep, that's the death bell for mine. Main cats and them sensors are goin' in the trash.
4everRS
October 21st, 2011, 02:51
Not 100% sure on this, but I think you may still need them. From what I've heard, the mototronics system needs to show an input. As far as I know, the sensitivity is dramatically reduced when using a "test-pipe" tune, but still active. Not sure, may want to ask a tuner.
yep, that's the death bell for mine. Main cats and them sensors are goin' in the trash.
kismetcapitan
October 21st, 2011, 05:15
true, but if they're coded out....?
Elevens
October 21st, 2011, 05:27
Not 100% sure on this, but I think you may still need them. From what I've heard, the mototronics system needs to show an input. As far as I know, the sensitivity is dramatically reduced when using a "test-pipe" tune, but still active. Not sure, may want to ask a tuner.
I run True Milltek Race Pipes (Downpipes from the Factory with no Cats) and they retain the O2 connection Points. This must signify that the O2 sensors must be retained, even though they may be coded out. This was also the case with the Secondary Air Induction pump (SAI). I wanted it Removed while the Engine was out. But my mechanic advised against it, since the Motronic might through a code even though its been coded out in the Tune. So I left it intact, even though it serves no purpose with no Cats in place. Better safe than sorry............................
4everRS
October 22nd, 2011, 05:41
Right. I think we use the term "coded out" a little too loosely. I don't think they are coded out, but more or less increase the amount of variability of sensors front-to-rear. I am no tuner, and it could have been a dream, but I seem to remember a conversation with APR I had about this.