The typical cost for an oxygen sensor repair, which is a replacement, ranges from $200 to just over $300 on average, as of 2015. Usually around $75 to $100 of that total price is due to labor costs.
Common symptoms of an oxygen sensor that needs a replacement include failing an emissions test or seeing the check-engine light turn on. There are a number of reasons why an oxygen sensor may fail, including contamination of coolant, oil or silicone. If there is fluid that has caused the oxygen sensor to fail, the source of the fluid must be found in order to protect the new sensor from suffering the same fate.
There are a number of things that may cause a code indicating there is an issue with the oxygen sensor, when the oxygen sensor itself does not require repairs. For instance, if the car has a leak in its intake or exhaust system, the code for an oxygen-system problem may appear. In order to resolve this issue, the leak must be repaired. It is also possible that newer vehicles, more recent than model year 1996, may have a universal oxygen sensor. These are inexpensive and low-quality parts that should not be used in a vehicle, as they can cause issues with the emissions system, according to Repair Pal.