Air Fuel ratio sensor LSU 4.9 sensor interfacing ( oxygen sensor )

Thread Starter

Ali Raza_1441110966

Joined Sep 1, 2015
air fuel ratio sensor used in cars, model LSU 4.9 boash , controller Chip CJ125 , i have searched alot, lots of info is also available but till now i am not able to understand its basic working principle of this sensor, because i want to use this sensor without the Controller chip, i want 0 to 5 volt output but CJ125 gives data in SPI format.
also i am confused in functions of different pin out of this sensor.

Kindly help


Joined Apr 28, 2013
Why are you building one when you can buy a cheap china made one for next to nothing or spend the money and get autometer gauges.


Joined Sep 1, 2012
wide-band O2 sensors are not that trivial - you need an external controller with a processor to control it and decode the output. Cheap controllers start at about $50, those would provide you with analog 0-5 signal you are looking for.