rn3037

I did the pre-cat O2's on my D3 and you have to take the intake manifold off. I attached the Elsawin how to below!

You definitely need the O2 sensor socket as you have to thread the wire through it. I also had to use black tape to hold the sensor in the socket while I started it by hand.

D3 A8 Pre-Cat O2 Sensors ELSAWIN Tech Writeup
https://drive.google.com/file/d/0B06...it?usp=sharing

aTOMic

Paul, thank you for helping people on AW for over ten years.

As I searched I found a great response from you - in 2003!

I wondered 1) is the Ross-Tech test you mention a test-run of the valve(s), the pump, or both. And (2) how do I do it.

I have tried to blow through the pipe ( by mouth, as Bentley implies) and it's sealed. I think I replaced the vacuum hoses to those valves but maybe I'm confusing them with the EGR valves... it's late, and I'm tired.

Muchass Grassyass!
Tomass

aTOMic

RN Thanks for that excellent doc. It's almost identical to Bentley, FWIW. Yeah, if the wire goes under the manifold it'd be problematic - at best - to do without manifold removal.

AdilY

My car threw code P0135 yesterday for Bank 1 Sensor 1. It is a 2005 D3 US SWB, 102kMiles. I just moved from San Diego to Seattle and I guess the sensor feels like myself, it is just too freaking cold here.
Anyway, I plan to replace both and checked the part price on Rockauto, Bosch part sells for about $100 each. Local shop wants to charge $260 for each sensor which I consider too much of a markup, that is just my opinion.
Assuming that the manifold gasket has to be replaced along with the sensors and ties and nothing else comes up, what would you think is a fair price for the entire job including parts? I am asking now before shopping for a more reasonable independent repair shop.
Thanks.

1Wasserwerks

Not that I am 100% correct here, isn't B1S1 the front sensor on the rear most cat on the right side? At least I believe it is on the V10.

Mister Bally

Take the cheap parts there and watch the labor rate jump. He has to eat too. Only way lower cost parts work is when you do the work yourself.
Also note that non-Audi Bosch sensors may have different cable lengths making the installation somewhat messy. This happened to me on a VW Beetle.

MP4.2+6.0

You just have to know how to read the (end of the) many digit Bosch number that is on the Audi OE sensors and convert it to the 5 digit short form used for the Bosch ones you can buy on Amazon, autohauosaz.com, etc. BTDT on the W12; cost 40% or less of discounted dealer. Exactly the correct lengths and correctly color coded at the plugs. 100% OES, just a bunch less $. Actually can still get a specific length one via Bosch that Audi superseded into a lesser number of "one size fits several"[not really well] that they apparently installed in post 2006 W12's on the drivers side.

MP4.2+6.0

B1S1 should be forward sensor, forward part of motor, U.S. passenger side on a W12 or S8. B2S1 would be same side but the rear cylinders. Gets confusing on trying to map these from the V10 and W12 to V8 though. On V8, B1S1 would be the whole U.S. passenger side, and then B2S1 jumps all the way over to the drivers side (which would be B3 and 4 on the bigger motors). S1 sensors are alway the forward position ("pre cat") ones.

1Wasserwerks

In this picture (not mine) it shows B1 (yes for the front 3 cylinders) but the cat is located rear-most from the engine. The connection for these sensors are located under the rear-most part of the belly pan area.
Yes you can also go to the Bosch website to find the number for replacement oxygen sensors. I think also cross-reference to a vw beetle, somewhere in the $80-90 range.

aTOMic

Thanks, interesting what Audi had to do to get those 10-cylinders past US EPA *****!

In that cross-reference are the wire lengths & connectors the same? Curious, not argumentative. I've personally used the "generic" Bosch lambda sensors without any trouble many times. I think the key is weather proof crimp terminals - they have built-in shrink tubing (i.e., the plastic part of the terminal shrinks to become one with its mate) covered with another layer of heat shrink tubing. Just bought with a heat gun or a crack torch (I have one in my "road" toolbox for soldering and shrink tubing)! Great reviews but kinda pricey. Have not tried one yet.




I've been crossing Bosch parts for my Alfa since (pre-internet!) 1989... The dealer would give an Alfa/Ferrari P/N and it'd be, say, $250. There was a tiny Bosch authorized shop down the road and he'd cross them over to the "root" Bosch number and it'd be $50.