I'm referring to the sensor itself. The meter can put out up to 9V momentarily in measuring resistance. I work with very sensitive components (mageneto resistive sensors) and we use diode clamps on our meters to limit voltage to 0.6V for resistance measurements, without them we blow them out as low as 3V.

I don't know how sensitive an O2 sensor is compared to these things. I was addressing Craig's response above to the tune of "measuring the voltage is safe it's resistance measurements you need to be careful of".

Point I'm trying to make is you are not going to damage an O2 sensor by measuring the voltage.

FWIW,

Chris