| Author |
Message |
    
Dragbikemike
| | Posted on Wednesday, January 20, 2010 - 11:40 am: | 
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Anybody tried to simulate an O2 sensor to allow richer tuning in ECM spy? I installed a 1M ohm resistor to fool the ECM and then dyno tuned for about 13.5 AFR. Bike runs great, but still get O2 sensor error code when running at constant moderate speed. |
Greg_e
| | Posted on Wednesday, January 20, 2010 - 11:51 am: |
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Narrow band O2 sensors are not an analog output in the sense that a resistor will not do anything useful.
What you will probably want to do is get a wideband O2 and controller, many of the better controllers allow you to simulate a narrow band output and change the point where the controller sends the normal rich/lean crossing point to the ECM. If the ECM never sees this change from low to high and back to low (rinse repeat) then it will throw an error code. Also in this case low is near ground, and high is only up around 1 volt.
http://www.aa1car.com/library/o2sensor.htm |
Dragbikemike
| | Posted on Wednesday, January 20, 2010 - 03:27 pm: |
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So that's why it takes a while to throw the code. I chose that resistor because it generated about the same voltage that I was reading on the ECM Spy monitor screen. If I could generate a random voltage swing in that range, would that make the ECM happy? |
Greg_e
| | Posted on Friday, January 22, 2010 - 01:17 pm: |
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You could probably find a 555 timer schematic on the web that would do what you need and would cost all of about $2. I know there are devices that people sell to do the same thing, especially for cars that have OBD2. Often when you change to a high flow muffler the second O2 will throw a catalyst not performing error because the exhaust is not staying in the cat long enough. There are several devices that send out a fake signal to replace the second O2 and keep the check engine light off. Not sure if it is the same signal that you need since the OBD2 second sensor should be a wide band O2. But I bet someone out there has made a narrow band O2 "simulator". The old Megasquirt project had plans for a "stimulator" board which had among other things a circuit to simulate the O2 sensor and was used to check and diagnose the Megasquirt EFI computer. You might be able to lift enough info from that schematic to build what you need. |
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03 XB9R O2 Sensor ECM Spy question