O2 sensor

i heard that an o2 sensor can go bad without a check engine light and i have some of the symptoms of a bad one so what is the easiest way to test if it is bad?

what are they

What are the symptoms you are having? I’m having probs with my idle, and no power.

im running rich, a little hesitation, and ill wash my car and 3 days later i will have tons of black specs all over my rear bumper. not getting as good of gas mileage as i should be, i just want to know the easiest way to test it.

maybe

do you have an air fuel meter? if not auto meter says that all the meter does is read how many volts the o2 sensor is giving off. I’m not sure if more volts means your running rich or lean. actually here is the actual link directly to the explination.

http://autometer.com/hp/index.html