both downstream O2 sensors running high.

[tomcat27]

I've replaced one of my downstream sensors 3X and the other downstream sensor once. 2002 Dodge LH. I can watch the data stream - both sensors are running high but not steady. generally .65 - .85 and normally staying closer to .85 than not. so... bad conincidence or a wiring problem? BTW - both upstream sensors are bouncing numbers correctly from .15 - .95

 

[yonyon]

This sounds like normal operation. If you snap the throttle open for a moment, to the downstreams swing down with a smooth curve and then creep back up?

 

[tinmanSC]

Do you have a check engine code with this? What is prompting your investigation of these sensors? Not ready to even call this a problem just yet.

 

[tomcat27]

The mil is illuminated. P0138 and p0158

 

[INDYMAC]

Do you have any exhaust manifold leaks?

 

[threeputtpar]

I know that some of the Bosch O2 sensors on Audis have had problems with the solder in the connections breaking and causing the issue you have. Can you access the plug and open it up to check the connections? Often it's just a matter of reflowing the solder.