how much do the o2 sensors cost to replace? i think mine are shot cuz i have been overly rich for about a year and a half. the car was turbo'd and the car ran pretty rich w/ the fmu and i never could get it adjusted exactly right. anyhow i yanked the turbo out and now i get a code one which i think is primary 02 sensor. i have the primary hooked up and no 2nd yet its stuck in my old downpipe. anyways i think being rich for all that time killed my 02 sensors. how can i tell if they are good or bad? and how much do they cost?

 

You could try checking the voltage which the sensor puts out ... and see if it changes with fuel mix.
There are some tests/checks that can be performed listed in the manual, ... price wise expect to pay Honda $150 or more depending on type. HTH