Can "O2 Sensor Circuit No Activity " cause in-car air quality problem ?
Thanks a lot

 

What dod you mean by "air quality problem"? If you are asking if you should fix the problem, yes, find out what is wrong with the circuit and if it's the O2 sensor, replace it.

 

I feel breathing difficulty in-car , eyes , nose and throat dis-comfortable when driving the car. Dealer can not find out the problem before the "Check" light turn on and find out "O2 Sensor " problem.
Thanks a lot

 

Anything is possible. If it's running too rich, that might cause your problem.

 

NR is correct, the engine is likely running rich which usually means unburned gasoline is traveling down the exhaust through the catalytic converter. This may be creating the noxious fumes that are bothering you, but more important, this situation will eventually burn out the converter. Get this fixed ASAP. The cost of the O2 sensor repair for labor and parts is miniscule compared to replacing a converter...which will also help you breath easier.