Hard to tell from the picture what is going on. I see two areas where the output voltage went low, but not sure if this was when the unit was triggered. I have worked with those as well. A lot depends on what vehicle, what type of sensor, how it is wired from the factory, and what the vehicle computer does with the info. Normally, you think of a 0-5 volt reading associated with a wide band. I worked with one vehicle that the computer would vary the voltage so there was a 0-5 volt range, but it was a narrow band sensor. The computer varied the voltage going in, and read the voltage coming out. The in voltage was subtracted from the out voltage to derive the amount of swing across the actual sensors 0-1 volt swing. This way the computer could detect an o2 fooler that created a fake tic-toc signal. The unit I was using was smart enough to apply the offset to the swinging input voltage so the ecu received the correct reading within the expected response range, only I was giving it a lean value so it would apply fuel to negate the value I was feeding it, resulting in a rich AFR that the vehicle computer was happy to supply during part throttle boost.