will these thread in or have to be welded in?<ul><li><a href="http://www2.partstrain.com/store/detail.php?R=audia419962007replacementusos-40001+audia419962007replacementusos-30001+&amp;B=Tj01ODQzJk5yPU9SKEFORChtYWtlOkF1ZGksbW9kZ Ww6QTQseWVhcjoxOTk2KSxBTkQodW5pdmVyc2FsOjEpKSZWaT0 5NTk4JTIwMTU3NCUy

Those will thread in but things won't be right or even very good with those installed.

Sensors are never weld-in... only the "bungs" that the sensors screw into get welded as when installing into steel headers. Stock bungs are cast into the cast iron exhaust manifolds then tapped after casting to accept threaded sensors.

one of them krapped out under 500 miles. only reason i knew was because i installed A/F meters. the left bank kept dropping out and throwing a code when the motor was up to operating temp. so, i ate 160 bucks in junk. unfortunately, i ordered them before i became a member of this forum, otherwise i would have had access to great information. so in a nutshell, buy bosch OE sensors. if you cant afford them, sell your house and get'em. o2 sensors play one of the the lead roles in the overall health and functionality of your engine.

dave

<ul><li><a href="http://www.autohausaz.com/search/product.aspx?sid=inplsm2aa2ray1553tgyroyi&amp;makeid=8 00002@Audi&amp;modelid=1008650@90%20QUATTRO%20&amp;year=19 95&amp;cid=19@Emission%20System&amp;gid=5132@Oxygen%20Sens or">http://www.autohausaz.com/

and still have the same results?<ul><li><a href="http://www.shokan.com/catalog/product_info.php?cPath=38_39&amp;products_id=41">http://www.shokan.com/catalog/product_info.php?cPath=38_39&amp;products_id=41</a</li></ul>

"Since all Bosch heated thimble type sensors are the same, just with different harnesses, one solution is to get the Bosch sensor for another car that doesn't command the same level of markup (my favorite is the #13913 sensor, used on various Fords but Bosch has come up with a 'generic' one that you can use as well) and splice it in to the Audi harness plugs. There's no problem with this, as long as you make a good electrical and mechanical connection on the wires, seal them properly against contaminants from the engine bay"

?<ul><li><a href="http://12v.org/engine/index.php?section=hw&amp;sm=o2">http://12v.org/engine/index.php?section=hw&amp;sm=o2</a</li></ul>

I was going to use<ul><li><a href="http://www.posi-lock.com/">http://www.posi-lock.com/</a</li></ul>

I have replaced all four O2 sensors on my 1996 A4 V6 with Bosch parts, but not the ones with the Audi cable/plug. Do a search for Mance's splicing technique, which uses small butt splice connectors and heat shrink tubing.

For the fronts, I used the Bosch 3-wire sensor which fits a 1992 Ford Mustang 5.0. These have been in place without a Check Engine Light for three years.

For the rears, I used Bosch 4-wire sensor part #13913 which is for an early 1990's Chrysler Concorde - this is the same part that Shokan supplies. I have had these on the car for about nine months, good so far. I spliced them on the car with the wires in place, which took a LOT of time; I don't know how much time would be saved by removing/reinstalling the wires, as they are hard to access.

Each of these sensors cost less than $40 at my local Autozone.