This video shows monitoring of the O2 sensor output voltage on a Federal model 1993 Honda Civic VX with a D15Z1 engine. As described on this webpage: ecomodder.com Pins D14 and D16 of the California model ECU (serial P07-A00) are hooked up to a digital volt meter, which you see in the foreground, and the tachometer is sortof visible in the background. The engine is started cold just before the beginning of the video. Lean burn is shown as a voltage above 0, and a lower air:fuel ratio is being used when the voltage drops into negative numbers. You can see that with the CA model ECU, the voltage spends a lot of time in the negative numbers while accelerating.
honda, civic, vx, ca, ecu, d15z1, fuel, emissions, smog, auto, economy, badur