Are there 2 or 3 different o2 sensors?

[mydreamcar]

Good Day.

My awesome Audi mechanic says there are 3 different o2 sensors I have to order. He says order Bosch, non-generic.
I called up Audi, they told me there are only 2 different o2 sensors.

My other mechanic friend looked on WorldPac, and they say only 2 different types.
They also looked at All Data, and they say 3 different types (078906265M, 078906265N, 078907265P).

I'm so confused!

Does anyone know FOR SURE?
Also, where can I get these Bosch o2 sensors cheap online?

Thanks a ton (as usual to all those who spend their time giving answers to people like me)
-Christian from Monterey,CA

[Timtheguru]

There are 4 O2 sensors on the S4, 2 front and 2 rear, The 2 front are the same, and the 2 rear are the same. All Bosch.

There are probably variations from different vendors, and one of those may be the generic splice in sensors.

[JKnight41]

I am in the process of changing all mine as well. Just use the bosch universal and splice in your wires. Saves about 1-200 dollars.

[getslideways]

Might have to do with harness length or something to compensate for the varying distance from the sensor to the harness plug mount on the firewall. Could also be outdated and superseded by a part to just cover both, as all I am finding for current offerings is a front and rear, then same part for left and right.

Although JHM still list two different parts for Left and Right Rear:

https://jhmotorsports.com/shop/catal..._56_60_100_155
https://jhmotorsports.com/shop/catal..._56_60_100_155

I think the rears had different colored connectors too but the length seemed the same, so again maybe the superseded part did away with the color coding so they wouldn't have to stock as much inventory:



However, if you are just getting the universal units to splice into the existing harness, then it will not matter

[mydreamcar]

Thanks ALL.

TimGuru; Thanks. Rock Auto, agrees with you and says there are only two types @ $85/per

JKnight41; Thanks. I'm worried that my mechanic (who I'll be giving these to install) will curse and throw wrenches at me if he has to splice into pre-existing wires in such a tight location. Though I'm open to your/other's experience with Universals.

getslideways; Thanks. I called up JH Motorsports. They picked up right away and seemed cool. They sell all three: The front two are identical. The rears are different.
Fronts @ $90/Each.
Right Rear @ $105/Each
Left Rear @ $105/Each.

I think I'll order from Rock Auto and save me some $50.

Thanks All!

[Taloras]

Another vote for universal. If your rears are shot, removing them and doing the splicing is super-easy, since it's all exposed and readily accessible.

[Timtheguru]

You would remove the old sensors to splice in universals, would be funny to try and do it in the car lol.