Voltage reduction O2 sensor

Thread Starter

homerdodd

Joined Feb 10, 2018
69
I have a stock car that I occasionally race. Since it is street driven, I need to keep it registered and pass smog. You may already know how an O2 sensor works. Look at my simple sketch I attached. I have an adjustable mixture kit I install for when I race, but the O2 sensor will throw it off when doing its job. What I want is to convert a spare O2 sensor with the 3.64v reference voltage supplied by the ECM to a steady .45v, (instead of fluctuating between the normal .1 - .9 volts in normal operation), which which keep the mixture proper for the race track. I was thinking a voltage divider inline on the signal wire, maybe? Can you give me a circuit recommendation with resistor and/or capacitor values, etc? Much appreciated, thanks.
 

Attachments

Last edited:
The problem with keeping a steady voltage is the ECU expects it to switch between lean an rich fairly often and will eventually cause a fault. Maybe will work for 1/4 mile runs since it should pretty much be rich the whole run, but circles or turns is a different story.
 

Thread Starter

homerdodd

Joined Feb 10, 2018
69
The problem with keeping a steady voltage is the ECU expects it to switch between lean an rich fairly often and will eventually cause a fault. Maybe will work for 1/4 mile runs since it should pretty much be rich the whole run, but circles or turns is a different story.

Yes, I know about the lean/rich. Just want the steady flow for the drag races. Would a voltage divider work or some other cap circuit?
 
Now I wish I had a definite answer. Just out of curiosity what do you have? What all is involved with the enrichment setup? What does the reference voltage go to?

Something wants to make me say it can be done, but you might be better off finding someone local to work with on it.
 
Top