Selectable Simulated Narrowband Signal Switching Point
Now you can select the switching point of the
Simulated Narrowband Output to force the ECU to maintain a richer or leaner
mixture than 14.7 AFR (Lambda 1) in a closed loop. A stock narrowband O2 sensor
switches at 14.7 AFR, forcing the ECU to maintain 14.7 AFR at closed loop. The
ECU operates in a closed loop at idle and at low throttle (low engine load). The Zt-2
"knows" the entire AFR range and is capable of shifting the narrowband switching
point to a richer or leaner region. The default NBSP is the same as a stock
narrowband O2 sensor, 14.7. You can program the Zt-2 to output as desired by the
ECU curve anywhere from 9.5 to 21.0 AFR. This could be used for better or for
Your engine was designed for 14.7 AFR at closed loop. Most engines will idle and
drive at a lean closed loop AFR 15.5-16.0. This leads to a significant fuel
savings! You can also force the ECU to idle on the rich AFR side to cover up big cam
A different than 14.7 AFR Narrowband Output
will increase the smog output and may harm your engine and catalytic converter.
Open the Zeitronix Logging Software. Connect the Zt-2 Wideband AFR Meter into a PC COM port and power up the Zt-2. Make sure the log graphs are shown on the screen. Open the Narrowband Switching Point menu by selecting Settings/Narrowband Switching Point
To Change the Narrowband Switching Point, adjust the number in the menu and click OK. The Narrowband Switching Point can be restored to a default value of 14.7 AFR by clicking on the Default Value, then OK.
All Zt-3s and Zt-2s rev 9 and above purchased after May 9 2006 are equipped with a Selectable Narrowband Switching Point feature.
You can check compatibility by accessing the Alarms window in the Zeitronix Logging
Software Version 2.0.5 or higher.