O2 Sensor wire colors?

[vbrock1137]

I plan on removing the cats on my '97 C230. I've purchased an O2 sensor simulator from eBay, but I'm not sure how to wire it. It needs 12v, ground and signal out, which would be the amount of O2 in the exhaust. I know I can find 12v and ground, but before I go cutting wires to find out, what else is there? I've been told there should be a temperature sensor as well...? I can't say that I know too much about O2 sensors. Other than 12v and ground, what type of signal would I get on a multimeter for any other wires?

Can anyone tell me the colors of the wires and what they are?

BTW, my car is registered in Oklahoma where they have no emissions inspections, so that's not an issue.

[alphanumeric]

well... I think your car would run like shit w\o an O2 sensor.. from what I know.. it measures exahust to see how rich or lean its running.

I would simply just re-locate the O2 Sensor to some other place along the Exhaust

[vbrock1137]

I believe the first O2 sensor reads how rich or lean the mixture is, the second one reads how effective the cats are. Once I remove the cats, the O2 simulator will reproduce the signal from the second O2 sensor telling the ECU that the cats are doing their job, even though they don't exist. The first O2 sensor will stay in place.

[manny]

Your typical wire colors on a 4-wire O2 sensor are:
Black = signal
Grey = 12 Volt ( O2 heater power )
White = signal ground
White = heater ground. ;)

[manny]

Originally posted by vbrock1137
Once I remove the cats, the O2 simulator will reproduce the signal from the second O2 sensor telling the ECU that the cats are doing their job, even though they don't exist. The first O2 sensor will stay in place.

Yes, providing the " swingrate " ( rich/lean counts ) are the same, as M-B designed it to be.
If not, you would have a " Check Engine " light. ;)

[benzaddict]

Originally posted by manny
Yes, providing the " swingrate " ( rich/lean counts ) are the same, as M-B designed it to be.
If not, you would have a " Check Engine " light. ;)


There should not be "swingrates" on a rear O2 sensor. The rear O2 sensor is only in place as a diagnostic for the catalyst and if it is oscillating (swingrate) it means that the catalyst has failed and is reading the same oscillations as the front O2 sensor. The rear O2 sensor should start off cold at about 450mv and slowly rise after about 10 minutes to around 700-725mv and stay "flatline" for the duration of the run cycle. So his O2 sensor simulator should not have "swingrates", just a constant voltage signal.