So I have bought a Spartan 3 Lite OEM and wired 12v H- and Electronics GND, and managed to connect linear output to ESP32 (via ADS1115). I was able to use the module for 2 hours (working perfectly) then after that AFR is erratic (switching between 0-5v). So I power cycled the Spartan module and also the ESP32, now its stuck at 14.7 afr (2.35) when tested vs a multimeter.
I have followed the troubleshooting guide and during start up, voltage is at 1.6xx for a few seconds then 3.3xx then after that stuck at 2.35.
When i do free air test voltage is still stuck at 2.35
But when i tested it with a lighter (gas), voltage shoots up to 5.00 then built in led blinks slowly then steady red light then goes back to 2.35v
Also I have tried to use Serial UART and during the free air test I have sent out a “G” command multiple times and it returns 8.8 and 50.0 AFR in random intervals.
Not sure if this is due to faulty sensor or controller. Is there like a command or sign that something is wrong with the sensor ?
btw english is not my primary language so sorry 
. I hope I have explained ot clearly
Update:
Sensor died… This morning I connected to Serial and after the initial heat up I can see the faint glow on the sensor tip yet when sending G command it returns 0 on sensor temp.
Already ordered another sensor online (clone only 
). Will update this thread soon
Interested to hear how the clone sensor works! Keep us in the loop!
Update: New sensor arrived (clone)
Immediately after plugging it in, after the startup procedure it heated up fairly quickly and after running a serial “G” command it returns 780 on temp, but AFR at 12.4, sometimes 12.5, 12.6 on free air 
, so i did a free air calibration using command “DOCAL” and it prompt me to power cycle the device.
After that AFR is erratic, jumps between 16AFR and 12.6 something (on free air), though when installed on the bike it does respond when i change rpm/tps and also if i try to richen/lean out center parts of the map, but I’m not sure how accurate it is.
Btw I’m measuring via the linear 5v pin and and converting it to afr using (voltage *2) +10. I’ve also noticed that when I issue the command to reset memory then do a power cycle the auxiliary heater led that I’ve installed doesn’t light up even when optimal temp is reached, only the built in led lights up hahaha now im even more confused
So what I did right now is set the 5v linear to 18afr, since in my previous experience with these kind of cheap clone they only go that far haha but I was using a different controller.
Sorry for the long and confusing post. I just want to know if somebody also has problems similar to mine (Free air AFR is erratic)