Weird AFR logging issue past certain enrichment

[ZLRob]

While I'm testing and trying out different WOT air fuel ratios, any time I run my lambda down around .80 the log shows me that after 4100 RPM a MASSIVE spike in lean activity running all the way up to 9.99 until my run is done. Almost like DFCO is kicking in, or the sensor is dead and then coming back after my WOT run, but upon checking my air fuel ratio gauge (AEM) during the run it shows me my lambda spot on around .80 - .81 like I command it until redline. If I run the exact same WOT run on a leaner mixture of .83-.85 the wideband logs without a hiccup every single time though.

This tells me it has to be a configuration issue or a logger issue. I don't think it can be a dying sensor right? For the record, my Denso sensor is about 5 or 6 years old now and has seen many wide open throttle pulls during it's time in my vehicle. I am obtaining wideband data via serial data by the way, not through OBD2. Anyone have any ideas what the heck could be going on? I can attach my channels configuration and log if need be so you can see exactly what I'm talking about.

Camaro Channels.Channels.xml
gen 6 zl1 layout w AFR err.Layout.Layout.xml
Log with AFR spike running richer:
12% pulley E70 run richer.hpl
Log without AFR spike running leaner:
12% pulley E70 run.hpl

[ZLRob]

Original post modified. Thanks in advance guys.

[TriPinTaZ]

I've seen failing wideband O2 sensors act up in a similar way. But I've also seen the same sorts of issues with grounding issues with the Wideband via serial port. Or should I say grounding to the serial cable which is highly prone to interference if the ground wire is too long or grounded near a radio. Odd issue for sure.

[ZLRob]

Hmm.. I may just have to give replacing the wideband a shot then as if I remember right, I ran the ground cable right on one of the main grounding locations by the driver's kick panel. When I do replace it and retest everything, I'll come back and update you if it worked or not. Given how old the sensor is, I can't say that I wouldn't be entirely surprised at this point if it is actually failing. Thanks for the insight Jason!

[TriPinTaZ]

Get an AEM OBD2 wideband and call it a day. Much more reliable and easier to log with a high refresh rate.

[ZLRob]

Get an AEM OBD2 wideband and call it a day. Much more reliable and easier to log with a high refresh rate.

I just wanted to update this and say that I found the issue. The air fuel ratio sensor itself had a pin that let go on it's detents and was barely making contact with the communications circuit of the wideband causing erratic miscommunications at random moments. I pulled the pin out, flared out the retainers, snapped it back in and it's holding solidly again. We're good to go and fully communicating at all times now.

Thanks for chiming in and helping out as always Jason. We'll call this case closed.