How Do You Test Your O2 Sensor Via Diagnostic Mode?

[Trav33]

Is there a way to test if your oxygen sensor is working?

I believe that if its not, the ECU runs a rich map, and ignores the o2 sensor completely.

I put in a new oxygen sensor approx 2 months ago, and had awesome economy. But it only lasted a month, and since then the economy has been getting worse each week - back to 350kms per 60L tank.

I've searched the forums, and found you can use a multimeter to read the sensor voltage - but is there also a "diagnostic mode" you can put the ECU into, to tell if it is using the sensor or running in rich mode?

[Trav33]

Boo!

Does anyone know?!

Is there an LED on the rear of the ECU, or is there a way to make your indicators flash a code?....

[Keeper]

Boo!

Does anyone know?!

Is there an LED on the rear of the ECU, or is there a way to make your indicators flash a code?....

consult cable? showed one of mine was reading 100 all the time

[Trav33]

Ah, don't have one of these...

Does the PowerFC show if the O2 sensor is working?

[benl1981]

With the PFC you can go into sensor check fuction and check the voltage is toggling between about 0.2v and 0.8v. A signal <0.5v means lean and >0.5 = rich. It should change every second or so at idle.

It still doesn't tell you that it is maintaining 14.7 AFR when in closed loop but give you some idea.

Edited March 28, 2007 by benl1981

[Trav33]

With the PFC you can go into sensor check fuction and check the voltage is toggling between about 0.2v and 0.8v. A signal <0.5v means lean and >0.5 = rich. It should change every second or so at idle.

It still doesn't tell you that it is maintaining 14.7 AFR when in closed loop but give you some idea.

Got my powerfc plugged in today, and i can go into the sensor check and see O2-1=0.00V

Is this the right sensor reading for the oxygen sensor.

If its a continual 0V at idle, does that mean my 4week old oxygen sensor is farked?!

[Baconer]

mine does the normal scanning when driving but on idle it sits at 0.00 so pretty keen on an answer aswell

[Trav33]

mine does the normal scanning when driving but on idle it sits at 0.00 so pretty keen on an answer aswell

Baconer - what does your sensor read while driving?

[Baconer]

jumps between .1 and .6 which is apparently normal(ish), only problem i have is on idle once car is warmed and occasionally cold it reads 0.00.

[Trav33]

Wow, i'm lucky if i see .04 or 0.06 - think my sensor has a bad connection or is farked.

[T04GTR]

or an ociloscope