Depends on what car you have, but it will probably cost you about 400$ or more.
$300 with labor
It just cost me $220.00
A Bosch O2 sensor, from NAPA, is $91 here in southwest Washington.
The cost to replace an O2 engine sensor on a Mitsubishi 3000GT typically ranges from $100 to $300, including parts and labor. The price can vary based on factors such as the specific sensor type, labor rates in your area, and whether you choose an original equipment manufacturer (OEM) part or an aftermarket option. It's advisable to get quotes from local mechanics for a more accurate estimate.
the price of the 02 sensor. under 20 bucks. and about 10 min of your time.
To change an O2 sensor you need to disconnect the wiring harness from the sensor. Use an O2 sensor socket and ratchet set to remove the old sensor and replace with the new one.
An O2 sensor unscrews just like a spark plug.
Remove the vacuum hose from the O2 sensor. Remove the wiring harness. Remove the O2 sensor retaining screws. Reverse the process to install the new O2 sensor.
You cannot repair an O2 sensor. Replace it.
i got one for 80 bucks at napa
Around 90-100 dollars
If you dont replace a faulty O2 sensor you will not pass emissions, you probably are experiencing bad gas mileage as well. Sensor replacement is usually easy and straight forward. Somewhere in your exhaust pipe the sensor just merely screws into the exhaust. You will need a special O2 sensor socket readily available in any auto parts store for about 10 dollars. 02 Sensors usually run between 60-80 dollars but can run much higher in some cases(heated O2 sensors cost much more) I have a 1997 Explorer and found the O2 sensors in the manifold pipe under the drivers side of the vehicle. It was very easy to replace, I USED A VISE GRIP WRENCH, IT WAS VERY TIGHT AT FIRST, SO I LIGHTLY TAP THE VISE GRIP WITH A HAMMER, IT THEN CAME OUT EASYLY. THE SENSOR ( MOTORCRAFT ) COST ME $62.00 + TAX. - NICK L.