Innaccurate Wideband Readings Between Gauge and EMS
 

Whats up guys. Got a question for you all. I recently installed an AEM UEGO wideband and hooked it up to my Haltech Pro EMS. On the Haltech gauge in the software, Im getting readings that are .1-.4 higher than the actual gauge itself. Is this normal or do I need to adjust something? Not sure whats going on here... Thanks for the help!

Not uncommon for this to be off that much between devices. The Wideband is going to be the most accurate coming right off the source, so go off of this when tuning. There may or may not be some calibrating you can do on your EMS, but im not familiar with that system to know.

Thanks for info Junky. So, are you saying the gauge itself is going to be the most accurate? I was hoping to use the data logging to help with adjustments/tuning. I guess I can go unplug the sensor and see if I get the same value between the two that way.

Yes that’s been my experience. If it’s consistently off a particular amount, you can also just keep that in mind when making EMS corrections. My Emanage shows pretty consistently .5 leaner then actual on wideband, so I keep that in mind when setting up corrections, or looking at the data logs.

My wideband is out also.

I'm pretty pissed off by it as I bought two serial gauges aswell as I thought this would be the best install.

Now I wish I'd of just bought a couple of standalone gauges

The only reasons for the software to not show the correct value are either:
1) you set your min and max AFR incorrectly in the Haltech software, these need to match the 0V and 5V values in the documentation for your wideband
2) your wideband and Haltech unit do not share a common ground signal for reference
3) your wideband is not providing a linear 0-5V output signal

The UEGO has been reported to be non-linear in its output in order to be compatible with the AEM Standalone EMS. Others have reported the documentation for the UEGO provides the incorrect 0 and 5V values. I would recommend some research or just live with the values being wrong.

Thanks for the help guys. I'm going to work on it a little this weekend and see if I can't get a better reading. My tune day at T1 is July 10 so the only thing I'm going for right now is conservative and safe. I may even buy a cheap beater to drive until then, but don't know yet.

Something to keep in mind as well for seeing which device is closest to reality. A 100% working tail sniffer at the dyno reads .5afr leaner then actual. As long as their sniffer is working properly( which can be hit and miss sometimes) You can get verification on where your afr is truly at. If there is any calibration you can do, you can base it off that. I always air on the Wideband reading, in my experience its always been .5 richer in comparison to the dyno tail sniffer, you can verify that by having the dyno shop run their 02 senor in place of yours as well. My Emanage happens to read what the tail sniffer does, which is just dumb luck. Real world testing verifications trumps any hypotheticals.

i just did a data log as i just switched to the 3.6'' pulley i bought off aj ''s2konroids'' and the logs and the gauge seem to read dead on but im running plx wide band i will be watching closer now to see if i have any discrepancies. 4 psi at 6000 rpm and 12.1 afr woohew! tx2k who's dyno are you using? jotech wants alot to rent for an hour but i also don't want to use some of the jack leg setups i've seen around the areahttps://www.s2ki.com/s2000/public/st...t-tip-wink.gif

I used Alamo Autosports for the first tune. The setup my car was on seemed pretty nice. But, as of now Im probably going to do a few street runs to make adjustments until my tune day at T1.