# Oxygen Sensor wrongly wired

**URL:** <https://community.ecumaster.com/t/oxygen-sensor-wrongly-wired/6274>\
**Category:** EMU BLACK / CLASSIC\
**Created:** [August 4, 2026, 12:34pm UTC](https://community.ecumaster.com/t/oxygen-sensor-wrongly-wired/6274 "2026-08-04T12:34:16Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![Moritz](https://avatars.discourse-cdn.com/v4/letter/m/58956e/32.png) [@Moritz](https://community.ecumaster.com/u/Moritz)\
**Post date:** [August 4, 2026, 12:34pm UTC](https://community.ecumaster.com/t/oxygen-sensor-wrongly-wired/6274/1 "2026-08-04T12:34:16Z")

</div>

Hi, by mistake I’ve connected lsu 4.9 as 4.2 to emu black. I’ve rewired it properly now but it’s not working. In the video you can see how it behave. Sensor checked with external controler and it’s working, so emu broken?

[![](https://europe1.discourse-cdn.com/flex013/uploads/ecumaster/original/2X/1/154b229018149ebbef4bba03870c4f66379942ab.jpeg "EMU Black LSU4.9") ](https://www.youtube.com/watch?v=QbvL2kcVgdw)

---

<div class="post-metadata">

**Author:** ![aces](https://dub1.discourse-cdn.com/flex013/user_avatar/community.ecumaster.com/aces/32/5896_2.png) [@aces](https://community.ecumaster.com/u/aces)\
**Post date:** [August 17, 2026, 5:42pm UTC](https://community.ecumaster.com/t/oxygen-sensor-wrongly-wired/6274/2 "2026-08-17T17:42:50Z")

</div>

Hi!

```auto
It is likely set to rapid heating, and it isn't active unless the engine is running.
Try setting it to "always active."

```