O2 voltage?

[jack-pot]

im wondering about my o2 sensor voltage. i was checking for a vacuum leak using propane and watching the o2 voltage. as i was moving the propane around i found a small leak and the o2 voltage went from .15 volts to .825. after i pugged the leak with RTV my o2 voltage when negative to -.12 and i couldnt get the o2 voltage to come back postive, even when i put the propane into the intake it stayed negative. just wondering what could possibly be wrong?

[vancouverbc]

I dont think the negative means anything. You just switched the leads. Voltage is voltage regardless of sign. Why were you checking the o2 sensor while looking for leak? lean equal .1 volts and rich is 1.0 while engince is running.