BlaCkPlaGUE

Heh, normally I will never ask for a quick reply, I can be very patient. However, im in the middle of multiple jobs with my seven! im putting **** back together AGAIN to permanantley stop any vac leaks, and I also planned another thing, to properly crimp/connect the o2 sensor.

See, the harness broke when I changed it in the summer, so I cut the wire, stripped it and wrapped it with my one wire o2 sensor.
Now after all this time, I got a nice electrical harness for it, and I start to strip the wire for the o2 sensor off the harness and notice something.

There are two connections! One of the connections is braided around a center insulated black wire!

wtf? I thought these cars were only one wire o2 sensors..

So, wich one do I connect, the black or the braided outside? or both?

Or do I need to buy a 2wire o2 sensor now...

please help.

thank you!

1SxyRXy

it should be the on wraped in the insulation. i remember always messing with my 02 sensor wire in my TII and because i could never get a good connection, i noticed there was a damn wire that kept getting in my way because it was wraped with the 02 wire. i belive the other one is for a sensor on the intake manifold or something

BlaCkPlaGUE

So the center insulated one? alrighty, thank you.

I appreciate the fast reply! now back to work ;0

1SxyRXy

np, when u solder it make sure u dont solder any of the insulation on it or you will get a bad connection

BlaCkPlaGUE

Well of course you were right (I crimped it, not solder) it was the center one.
The outside braided wire around the insulated one is not an actual connection! its just some kind of protection or something. After checking it out I don't even think its supposed to conduct electricity.
It could be shielding for EMI? thats all I can think of.

Man im so pumped, its 2:30am and im finishing up my seven, getting all this **** done, feels great.

1SxyRXy

sheilding i belive is for heat and interferience

BlaCkPlaGUE

Funny how the bosch one I bought has none of the braided insulator.. bosch quality I guess.

I spose theres really nothing to shield with a one wire o2 sensor, nothing could really interfear with the signal. I'm guessing that heat is the primary thing that the shielding is for.
meh, mystery solved.

Kenteth

heat and the funky magnetic field it has causes voltage drops and spikes on the line which leads to a a check engine light...

BlaCkPlaGUE

I've disconnected the wire before while the engine is running and I've never gotten a CEL. Are you saying that EMI can go into the computer via the unshielded wire and give you a CEL?