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PLX SM-AFR, Air/Fuel Ratio Wideband

SEMOSMAFR_mainPLX – SM-AFR (GEN4) Wideband O2 Sensor and Module

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We’re proud to introduce our next generation wideband oxygen sensor controller with intelligent health monitoring technology. Our new Gen 3 Wideband Sensor Module implements PLX Devices new intelligent health monitoring technology where the oxygen sensor is meticulously monitored every 2mS (488 times per second) to obtain peak performance, accuracy and reaction time. The Gen 3 SM-AFR adds 3 new sensors: sensor life ,displayed from 0-100%; oxygen sensor reaction time, displayed from 10mS-1000mS; and Voltage, displayed from 9-20V.



The PLX Air Fuel Ratio Sensor Module accurately measures the wideband air fuel ratio (AFR) of any internal combustion engine. It comes with a Bosch LSU 4.9 wideband oxygen sensor. Up to 32 Sensor Modules can be daisy chained together from the PLX iMFD line for modular tuning and can be connected to any PLX Multi Gauge through the digital serial output port. This Sensor Module can also be used as a stand alone unit capable of interfacing with third party hardware where both the digital output and the analog output are available simultaneously. The SM-AFR works with gasoline, bio diesel, ethanol, methanol, E85, LPG, and CNG. Advanced soft start technology prolongs the O2 sensor life. The SM-AFR never needs to be calibrated and is accurate to 0.1 AFR with a tuned critically damped controller circuit for an ultra fast reaction time. The SM-AFR has a effective measurement range of 0.68 – 1.36 Lambda. It is also capable of reporting lean readings all the way up to free air with a DM-6 Multi Gauge.


  • New Sensor: O2 Sensor Health
  • New Sensor: O2 Sensor Reaction Time
  • New Sensor: Voltage
  • No Calibration required
  • Soft start technology
  • 2 analog outputs
  • 1 digital input, 1 digital output
  • Bosch LSU 4.9 Sensor
  • Compatible with multiple fuels
  • Sensor is hand tested
  • Digital precision













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