Alright so I mentioned this two months ago and seemed to partially fix an issue. I’m trying to get my car retuned (AEM EMS V2) and I have a wideband (AEM X-Series EUGO 30-0300) to connect with it for getting the etune process done. Before, the WB was wired up weirdly but on AEMTuner it worked until it hit a reading of 14.3. The gauge would continue to read correctly but the O2 on Tuner would stop reading leaner than 14.3 and it would freeze there but if readings dropped below 14.3 they would match again. AEM claimed beforehand the gauge was faulty so they sent a new one, after more troubleshooting I sent the EMS but again, no issues.

I got the EMS back a few days ago. I redid the wiring cleanly using an accessory port for power, bolt on hood latch for ground, pin C16 for white wire and interchanging between pin D9 and one of the sensor grounds (C7 or C18) for the brown wire.

My issue now is upon startup, both readings match within 5% but after a few minutes, O2 reading pauses and they read completely differently so I still can’t log for my Tuner. O2 Voltage reads around 2.3/2.5, I’m not sure what that means but I remember AEM support telling me to check that a while ago, but they really aren’t helping at this point.

Does anyone know what could be causing this issue and how to fix it? My next step is just giving up and finding someone who can fix it for me. If anyone’s running the same setup, photos would help. Feel free to reply on here or dm me on instagram @alan.s2k

I just want my car tuned again :/

 

I don't have the X version, I have the one just before that so the way I wired mine was ignition switch for power in the under dash IGN port then grounded it in the same area near other stock grounds. The only wire running from the wideband to my Series 2 is the white wire (C16) in place of the stock O2 wire. No cutting or splicing. I de-pinned the stock wire and pinned the new AEM wideband wire in its place. I never had the same issue as you though. My gauge can go all the way beyond 20 until it goes "blank" like when I'm coasting in gear and the injectors have been shut off so it reads the full spectrum as you'd imagine. My tuner calibrated the gauge with the ECU through an iterative process on the initial tune.

Sorry man, sounds like an annoying issue to have :/