o2 question....

[kenf]

Quick question,
My o2 voltage reading at idle is from .30 to well over 600...cross counts are way up also...totally stock...34,000 miles...does this usually denote the sensor is failing? All other readings are within normal perimeters...idle could be better.
Thanks in advance.

 

[wickedmotorhead]

ME TOO

I have the same problem (mines not stock though). I get those same readings all over the place. Someone please help us understand what this means. Thanks again.

 

[DavzGN]

Normal

At idle, your O2 reading should be all over because the computer is crossing between rich and lean. The crosscounts tells the number of time the O2 has crossed stoich. It's only at WOT when in open loop where you don't get cross counts that you want the O2 in the hi 700's or low 800's (depending on scantool).

HTH
David

 

[ijames]

To add to the first answer, with an aldl scan tool like TurboLink you should see 10-20 crosscounts per frame at idle, and 20-40 per frame cruising at 55-65 mph. You should regularly see readings under 150 mV and over 800 mV. When a heated sensor starts to die from lead it will lose "range", and you won't see readings over 800 or 700 mV in closed loop.