Zt-4 Dual Wideband Air Fuel Ratio Meter


Zt-3 Wideband Air Fuel Ratio Meter and Datalogging System


The Zeitronix Wideband Air/Fuel ratio meter and datalogging system is a high quality, stand-alone system for use with carbureted and electronic fuel injection engines.

The new Zt-3 has the same high quality, high precision air fuel ratio readings as our signature Zt-2 wideband. The Zt-3 supports wideband air fuel ratio and lambda readings, adjustable simulated narrowband output and a new configurable linear wideband output for ease of use with engine management systems and 3rd party gauges.

The new Zt-3’s dimensions are only 3 by 2 by 1 inches.  The case includes slots case for easy zip tie mounting in a tucked away location.

Installation instructions
Zeitronix Data Logger Software

Zt-3 Wideband

Dimensions:  3″ x 2″ x 1″
(76mm x 50mm x 25mm)

Configurable Switching Point of
Simulated Narrowband Output

Replace the signal from your stock narrowband oxygen sensor for increased fuel savings or smoothed idle RPM.

Adjustable Narrowband Output

Configurable Wideband Output

Match the Zt-3 Wideband output to your engine management system, data logger or a 3rd party gauge.

Volts  AFR
AFR vs Voltage Table


Zt-3 SystemNo matter if you have a stand alone engine management system, a piggy back fuel control or a carbureted engine. The Zt-3 Wideband Air Fuel Ratio Meter is a must for serious tuners!  Finally you can tune for more power, closer to the edge, precisely monitoring Air/Fuel ratio and datalogging up to 9 hours of data with a blazing rate of 65 samples per second per graph. The Zeitronix Data Logger Software can be utilized as a real time display when using a standard Zt-3 kit with or without the ZR-1 or DashDAQ displays.

On Board Diagnostics (OBDII) is not required but may be monitored through use of the DashDAQ II XL display which reads and clears engine error codes, log Zt-3 Wideband System and OBDII data and has many additional performance features.


Very simple installation – connect two wires to +12V and ground and place the O2 sensor in the exhaust stream and you are ready to read AFR!  A simple LED indicator displays off, warm-up and running modes.

Additional information is available for setting up the configurable linear wideband output with your particular engine management system.

Zt-3 Specs

  • 0.1 AFR accuracy
  • Operating voltage 10V to 18V
  • Switching power supply for oxygen sensor heater
  • Precise sensor temperature control
  • Reverse polarity protection
  • Integrated self resettable fuse
  • Positive lock connectors
  • Protected inputs and outputs
  • Flexible Plug and Play Sensor Harness with a small, easy to route through the fire wall, connector
  • Kits available with or without the wideband oxygen sensor included
  • Easy to install plug and play kit
  • Adjustable Narrowband Switching Point
  • Configurable Wideband Analog Output


  • Bosch Wideband O2 sensor Input
  • Simulated and adjustable switching point Narrowband Output to feed a stock ECU
  • Linear Wideband Output (configurable with a default setup of AFR = Volts * 2 + 9.6
  • Serial data output to the Zeitronix ZR-1 AFR or DashDAQ displays
  • Serial data output for real time datalogging (PC laptop required)
Input / Output Range
Lambda1.43 to 0.64 Wideband
AFR21.0 to 9.5 Wideband
Analog Wideband Output0 – 5V (configurable) see 0 – 1V
Narrowband Output0 – 1V (configurable rich/lean switching point)
Dual Channel Wideband AFR
Dual channel AFR readings are available in multiple configurations from individual ZR-1 AFR Gauges connected to two Zt-3s to combined Zt-2/Zt-3 configurations using a ZR-2 Multi Gaugewith optional Black Box Data Logger. Many additional configurations are also available.

  Multiple Widebands with Black Box Data Logger and Optional Display

Zeitronix Datalogging Software
The Zt-3 communicates with the PC Laptop via the serial port. The 
Zeitronix Data Logger (ZDL) software records up to 9 hours of data per single file. Many different screen display options are available including plots, text and dashboard views and uses a black plot background for easy night tuning. Logging start, stop and pause are accessible from keyboard shortcuts. The ZDL software supports excel CSV and text data export.

Win98/NT/2000/ME/XP/Vista/Windows 7 compatible.
You do not need P4, P3 or even P2 laptop. We understand that you want to leave your new laptop at home and dedicate the old one to car tuning. We give you well optimized software. If your laptop is capable of running Win95 and up it is good enough for the Zeitronix logging software.

The digital gauge screen option could be used when purchasing the Zt-3 without a display.

Zeitronix Data Logging Software Download.

Standard Zt-3 Kit:

  • Zt-3 Wideband Controller
  • Bosch 5 wire Wideband Oxygen Sensor [optional]
  • Oxygen Sensor Harness (10 feet length)
  • Signal Harness
  • Serial datalogging cable with RJ-12 to DB-9 converting plug
  • Instructions
Optional Displays:
  • ZR-1AFR and Lambda Display
  • DashDAQ Touch Screen Display