RubyRedV6

Does that mean that it needs to be replaced?

CrazyCab

if your looking at the signal wire while the car is operating then .5 is ok. Its how an oxygen sensor works, it tell the ECU whether the car is running rich or lean by a value from 0 to 1 usually in .1 increments. If i recall correctly if its closer to 0 or .1 then your engine is running lean, if its up around .8 , .9 or 1 then the engine is running rich. The ECU uses these values to adjust fuel mixture accordingly.

RubyRedV6

I have measured the resistance across the sensor itself. I have read in an article that the resistance shudnt be very high on the sensor and if it is then the sensor needs to be replaced. But i am not sure what the original resistance of the sensor is..or even if I am measurin it correctly.

CrazyCab

If your oxygen sensor is gone, your check engine light should be on and it should throw a code for the oxygen sensor.

RubyRedV6

on the newer spec models in South Africa.
Took my car to a guy and according to him there is a fault code on the sensor. I think I will replace it this weekend and see how goes it.

nothing

Resistance is measured in ohms. You are talking about voltage, measured in volts.

E-Town

Needs to be one in there, it's part of the ECU circuit. You might want to check the bulb.

nothing

The ECU works fine with or without it.