O2 Sensor Simulation
 

Hello.

My engine (Loncin RE250) runs lean from the factory and I would like to enrich the air fuel mixture since I'm thinking of installing a full exhaust on it. The problem is that that the ECU that came with the bike isn't an original Delphi but a Chinese copy called Wantao, and from the tuners I spoke with, the ECU has its calibration map locked and can't be reflashed so ECU tuning is a no go.

I started searching for more solutions online and came across an O2 sensor simulation method which tricks the ECU into pumping more fuel by lowering the voltage reading on the sensor with a resistor on the positive wire, tricking the ECU into thinking that it's running lean and in turn, telling the injector to pump more gas enriching the AFR.

So my question is: how well does this actually work and is it possible for me to do on my bike?

Thank you in advance! :thanks:

It would be intersting to see whether changing the O2 output from the sensor would work. exactly how does the sensor control the ECU, is it just a voltage output and if so you could perhaps lower it but can not increse it with resistors. I have tried adjusting the resistance of the input air which made the mixture richer and helped with the idle speed but think the effect goes away when the 2 sensor takes over. Do you have any idea what the resistance vale would be to add to the signal output.

From what I've read, through voltage output from the 02. Voltage signal is around 0.1-1.0 volts. If the O2 sends 0.1v, the ECU reads it as lean and starts pumping more gas, if the O2 sends 1.0v then the ECU reads it as too rich then cuts the amount of gas on the injector.

That will make life a little difficult as we will need to increase that voltage to make the ECU make the mixture richer.

Hang on I think I have that all wrong,If the sensor output is made lower The ECU will increase the fuel until it gets to its target value so a resistance in the sensor line should make the sensor output lower.