2001? my check engine lights on. got a computer diagnostic test done and they say nothing wrong with engine. only the sensor is dead. part cost 40 bucks, if i have them do it takes 1/2 hr charge $185, however, if i just want the part it will only cost me $40. how can they charge over 140 for 1/2 hr work???any know how?

$40.00 for an O2 sensor is very cheap. As far as the price of installation, that is way to high. I've replaced a few O2 sensor and nothing more involved than disconnectiong the wire and removing the old O2 sensor.
I think they may have gotten the price and work backwards. It probably cost $185.00 (especially if you buy it at a dealer, may get it cheaper at your local auto store) for the O2 sensor and $40.00 for the labor. I just bought a heated O2 sensor for $123.00.

the sensor is on exhaust, takes special tool ,can by at auto supply,- disconnect ground on battery ,un plug sensor use tool ; to remove sensor, make sure new sensor looks same plug , apply thread compound to threads only/ small amount tighten, plug sensor in. hook ground on battery