I think I need to replace my oxygen sensors, but I can't find a resource on how to do it. Can someone direct me to a resource? 1998 A6 Quattro.

Thanks!

CV

 

it was on a 2.7T but i would assume the setup is still pretty close too the 2.8. i just did it 2 days ago, basically my words of wisdom would be to get an O2 sensor removal socket, a butt load of extention (like 2 feet or so) and a breaker bar (they will be very tight). for the lower O2 sensors just go at them with the socket and the breaker bar its really easy. but the upper ones are pretty bad, at least for the 2.7T probably because of the two turbos hanging off the exhaust manifolds. still i would assume these will be tough for you too. go under the car and stick just the socket on the sensor then come back up top and fish the 2 feet of extention down to meet the socket. you will probably have to go between the back of the engine and the fire wall dodging some wires and hoses on the way. Again i cant speak for the 2.8 but on the 2.7T i had to remove the accordian intake hose and the coolant overflow tank to be able to get the extention down to meet the socket. all together it took me about an hour of fighting with the car to get all 4 sensors out. sorry for all of the "maybe's", "probably's" and "possibly's" because im not sure how different the setup is for the 2.8. its not hard work but sometimes i found myself quite frustrated. good luck

 

Are you getting emmisions codes?...If so, which ones?

 

S1 B2 - this is driver (US) side upper one, I plan to replace S1 B1 as well as soon as find another at a decent price.

I posted some details but pretty much what A6turbo630 says is how I found it too.

Someone here suggested crowsfoot wrenches but they were no use to me, I found the O2 sensor socket an abosolute must-have.

I will try to find my post but I did take some photo's, they are in my P Poster - found.

I probably did not need to remove the Y pipe but it looks as if would help but in reality it does not really.

One of the hardest parts is removing and re-installing the cable. It is really tricky to get at the clips holding it up.

It looks as if S1 B1 is a lot easier to get at.

The secondary sensors are only for monitoring the perfromance of the cats and AFAIA they do not effect performance or throw CEL's.<ul><li><a href="https://forums.audiworld.com/a6/msgs/601889.phtml">From when I replaced S1 B2.</a></li></ul>

 

I did my 2.7T a few months back -- both front (pre-cat) sensors (I used VW sensors fitted with Audi connectors). Here's a quote from an earlier post: "In place of the Audi O2 sensor, get a couple of VW sensors, part # 06a 906 262q for about US $25 each and then Audi plugs, part # 3a0 973 334 for about US 80 cents each. Break the plugs from the VW sensors down to metal connectors and blue seals [this can be done easily in a vice by closing the jaws on the VW connector lengthwise -- no harm to the electrical connections/wires] and connect the ends to the Audi plugs and install. The wires on both VW and Audi sensors are numbered on the plugs -- mark each wire and connect to the appropriate number." I've got both a socket and a crow's foot O2 sensor wrench, but the crow's foot worked better for me -- it _is_ possible to get it into a narrow slot on the driver's side (to the left as you're facing the sensor), but there's a relatively narrow angle of turning room, so you have to lift the wrench off and reposition part way through each turn. The passenger side sensor is more accessible. The crow's foot doesn't require clipping or severely bending the electrical leads, unless somehow you have a particularly deep socket. I used about four feet of extension and -- very important -- a wobble extension for connecting to the crow's foot. It may be possible without one, but you can save yourself a lot of grief finding the right position with a wobble. The series of extensions came out over the fender, from which it was fairly easy to apply the requisite force. Undoing the originals turned out to be like unscrewing a spark plug -- a fair amount of resistance, but once they give, they're loose. Somehow, I was expecting them to be more stubborn. In fact, the sensors are fitted with similar compression gaskets. To apply torque I used a 1/2 inch breaker bar in combination with a 1/2 to 3/8 converter. I've got a bunch of pics of this escapade and have been meaning to do a write-up for a while, but just haven't found the time. Best of luck.

 

ones.

I think we are well and truely stitched up with OEM parts prices.

How can they justify charging more here than in the US?

It must cost a fraction in shipping charges to bring the parts here and distribute them so why are they so expensive?

A genuine Audi O2 sensor from my local main dealer, Lister's, is about ?140 and the VW one from my local VW dealer is about ?135.

 

Well, I guess that's typical of prices in England. Except for a few odd items, such as Jacobs Cream Crackers, pretty well everything is more expensive there. I find that a Canadian dollar goes farther in Canada than a pound does in the UK. So far as the O2 sensors go, I'd suggest exploring sources within the UK on the web first (i.e. locating a supplier who'll charge something like 10 - 12 pounds, and if that fails, investigating shipment to Britain from a US supplier like Impex or Autohaus Arizona -- whatever duties/taxes/postage are involved, that would surely have to be cheaper by far than the prices you quoted). Good luck.