I`ve been searching for days now and i CANNOT find the O2 sensor is supposed too connect to the engine...im starting too think it simply doesnt exist because there isnt even any pictures of it online.....I`ve got a 91 S5 T2 LHD

 

The O2 sensor connects to the exhaust, specifically, the downpipe after the turbo.

 

i think he is wondering where the other end of the wire goes, because i am having the same problem. impossible to find

 

Correct, now where is that f**ker..i spent all yesterday trying to locate it haha

 

i ran out and took a picture with i phone for you, but for some reason my computer is being stupid and wont let me upload it to the computer. i pm'ed you my email, so just email me and ill send you the picture. idk if the s4 tII and the s5 tII is different (as mine is an s4) but it might give you the general direction.

 

Gotcha. Then let me try to be of actual assistance. The plug on the harness side looks like it is wrapped in close with the BAC valve plug. I have pictures currently uploading from my phone to Photobucket. Just a couple more minutes...

 

 

http://i71.photobucket.com/albums/i1...6/DSC00053.jpg

THIS little rascal located behind my alternator? I read another thread about that connector and that thread had me convinced that plug was part of the cooling fan system....argh

 

That looks similar, but not quite what I have, also a 1991 S5 TII. Here is a picture of the connector on the harness side.

 

Is there any way i can id the connector ive found with a multimeter in some way?

 

that wire comes off the engine harness on the passenger side under the intake manifold near the ECU ground on a s4 im not sure bout the S5 tho.

 

Ok so i was under the impression that this is the connector that has fallen off my O2 sensor wire on the sensor itself..IF that is correct then the connector i found behind my alternator is NOT the correct connector...

http://i71.photobucket.com/albums/i1...6/DSC00072.jpg

Below you will find a linked pic to where i found the connector in question...again they do not fit together..I might have too check below my lower manifold as a few others stated above
http://i71.photobucket.com/albums/i1...6/DSC00063.jpg

 

Yes, that is the sensor side of the connector.

 

Ok, search goes on, ill keep ya posted :P

 

EUREKA? OK...so i might have made a few discoveries concerning the location of the O2 sensor on the harness-side..Look below -->

FIRST! A few facts about the car

*Engine has been replaced with a lower mileage engine that has been ported
*The Engine was installed by another rotaryhead for a low private cost done in my own garage by him one weekend. (Im stating this cause this might or actually MOST LIKELY means the harness isnt placed as it originally was)

SECOND!


I can find neither my BAC valve plug or my O2 sensor connector where it should beside the lower manifold....ergo...

What i suspect: -->

See the white and black connectors ive marked on the pic....those look SUSPICIOUSLY like the BACvalve plug and that black connector on the harness-side is identical to the one you have Jerry...the white suspectedtobe BACvalve connector isnt plugged in anywhere atm...could the black connector actually be a misplaced O2Sensor connector which also is the reason i annot find my BAC-valve connector where it should be concidering these 2 connector Exit the harness at almost the same place?









Long story short....the 2 marked plugs in this picture could be my BAC connector and the black one a misplaced O2 sensor? And if so WHAT is the O2 connector plugged into now? Its a plug and wire that runs down the blue line and dissapears under the belt hub there

 

That's them. The white is the BAC valve plug and black is the O2 sensor plug, just as you suspected.

I'm not sure I follow. Is the blue line in the last picture tracing the path of the sensor wire part of the connector or the harness side of the connector? It looks like it follows the path of the sensor. If so, is the sensor just dangling somewhere on the wrong side of the engine bay? Or did he find a magical new place to plug one in?

Also, if you look at your downpipe - is there an O2 sensor plugged in right now? Or is there just nothing?

 

Too answer ur last Q first, yes i got an O2 sensor with wiring but the plug itself has been torn of so its just a wire atm on the Downpipe O2 sensor....

And i dont know about the conenctors but the loose connector fits my BAC valve like a glove and the (or what i THINK is the O2 wireplug on the harness side) is plugged into a cylinder looking thingy underneath my P/S. Ill post up pics explainging it all abit better Thing is i dont see anything about any plug needing too be connected onto my P/S...and if there was it certainly isnt shaped the same way as the O2 sens plug...gimme a few mins for the pics

 

Ok, so dont get dazzled by my insane Photoshop skillaxes...i wrote abit on the pics...did that make it any easier...or worse too understand?

So we start behind the alternator and besides the Manifolds where it all starts...the believed BAC and O2 Harness plugs seem to run in the same wire system...which makes me believe this is actually the Emission Harness...



On this pic u can see the plug that is identical too the O2 Sensor plug coming from the Downpipe... and where it runs...



Until it ends up underneath a cylindershape on my P/S steering :S.....

 

Haaahahahahahahaaaahahahhh omgicanhaaahahahhaha...nono wait im not done yet...haahahahaaa.....ok so..for the past 3 years my 02 Sensor Harness plug has been connected to the P/S Oil pressure switch plug.................what does that mean to the car actually?

 

Possibly nothing. The engine can function without an O2 signal. At least now you may have figured it all out.

 

Yeah but what about the P/S Oil pressure thingy..Means the Power Steering hasnt worked since this misconnection was made? ..... :S

 

Probably. Once you get everything hooked up properly, you can determine if there was any lasting damage.