Question about scantool and 02 voltage

95Cobra302

Founding Member

Apr 9, 2002

394

3

19

Daytona Beach, FL

Feb 5, 2006

#1

• Feb 5, 2006

• #1

Looking at the real-time readout of my scantool while it was idling showed the 02 sensor voltage for number 2 about .30 to .50 while 02 sensor number 1stayed at .00 volts. Does this mean that maybe the sensor is bad or is this normal?? It showed no codes and everything else passed. If anybody knows anything about these voltage numbers please let me know.

 

HISSIN50

"How long does it take to get help in here?

15 Year Member

Nov 29, 1999

31,179

34

129

Feb 5, 2006

#2

• Feb 5, 2006

• #2

AFAIK, the stock O2's will switch from .1 to .9 volts; they do this several times a second. As the sensors age, the frequency with which they switch and their amplitude, will become reduced.

In your case, I would check the wiring values at the O2 to make sure you have the ingredients to allow the sensor to provide a signal return.

Good luck.

 

zenboy99

Founding Member

May 12, 2002

2,212

0

47

Madison, WI

Feb 6, 2006

#3

• Feb 6, 2006

• #3

Did you try revving it up and see how they change? For awhile I had one O2 always read low voltage at idle but would bump back up to normal when I'd drive around.

I'm having the exact same problem now. My left O2 doesn't ever go over 0.1 volts even though my wideband in that pipe is reading normal with the right O2.

 

95Cobra302

Founding Member

Apr 9, 2002

394

3

19

Daytona Beach, FL

Feb 6, 2006

#4

• Feb 6, 2006

• #4

I'll try different rpm's and see if it changes.

 

95 Laser GT Ver

New Member

Mar 7, 2004

29

0

2

Orange County, CA.

Feb 9, 2006

#5

• Feb 9, 2006

• #5

The scan tools do not work correctly for 94-95's when reading O2 sensors. I was having the same problem and thought my sensors weren't working. After spending money for new sensors with no change, I took my car to my tuner and he had the same problem with his professional equipment. He ended up having to jumper wires in the equipment to get it working.