# Need o2 sensor help (down-stream)

**URL:** <https://forums.speedlife.net/t/need-o2-sensor-help-down-stream/252314>\
**Category:** Shift518 Automotive\
**Created:** [May 27, 2010, 9:15am UTC](https://forums.speedlife.net/t/need-o2-sensor-help-down-stream/252314 "2010-05-27T09:15:30Z")\
**Posts on this page:** 1\
**Showing post:** 9

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**Author:** ![offroadzj](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/offroadzj/32/6428_2.png) [@offroadzj](https://forums.speedlife.net/u/offroadzj)\
**Post date:** [May 27, 2010, 4:50pm UTC](https://forums.speedlife.net/t/need-o2-sensor-help-down-stream/252314/9 "2010-05-27T16:50:57Z")

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> [@Next spring...](https://forums.speedlife.net/t/next-spring/32212/58):
>
> Put your meter’s red lead on the gray and the black lead on the black.

I did that and thats where I got around 8v… but I dont think that is correct b/c I am pretty sure that one is a “to” wire and one is the “from” wire which would mean they are both positive. I reconnected the o2 sensor and we’ll see what happens. If it trips another CEL, I might try this:

> **[AudiWorld Tech Articles](https://www.audiworld.com/tech/eng53.shtml)**
>
> AudiWorld was created to maintain the most comprehensive collection of Audi information anywhere in the world. Site includes Forum, Tech, Polls, Gallery, and more!

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