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Hello and thanks for the question. If i read it correctly your check engine light has illuminated you took it to a mechanic he pulled the codes, and tested and told you you needed an o2 sensor.
The 02 sensor and your car has 4 of them, they screw into your exhaust manifolds and there job is to measure the amount of oxygen in your exhaust, and report that to the computer, which uses that information to either richen or lean your fuel. Now if it fails the computer software goes into open loop where it runs off a base calculation, which keeps your car running but fuel economy and performance suffer. An 02 sensor has a life expectancy of about 100 to 150k miles as long as it lives in a healthy environment, meaning no skips in engine. It is important to note that there are two ways the sensor can flag a code one would be where it stops functioning as a sensor or starts reading slow the other would be if the heating element that is used to heat the sensor up fails or goes open, think of it like a heating element in your hot water heater, now if the code is due to a failed heater, and the sensor still functions otherwise you would have no idea other than the light being on. So to answer your question correctly i would like to know the code it has set,
If it is the heating element i have seen the sensors run a long time, and the heating element failure could be due to a power loss such as a blown fuse or faulty relay. I hope i have helped you
Yes sir if it was a heating element failure it would illuminate the light for that, your mileage is a little low for a sensor failure id bet your heating element failed. That seems like alot for a sensor i know over here in the states you could get them all four replaced for that and more.
could you get a second opinion or there alot of shops close to you
May i help you any further with this, if i have satisfied your question kindly give me a positive rating for it is how i receive credit for helping you, and please know any follow up is covered say if you want to get the code your setting and give it to me i will research it and advise you further. I thank you so much for using the service and your complete satisfaction is important to me
The labor time should be like 42 minutes and honestly you could do it yourself it just screws in and has a connector and on your car there not that bad to access, i would advise you to save yourself a ton, matter of fact you could buy all four and have money lots of money left over
as for the four being identical i beleive the two front are the same and two rear are same, but i am not a parts man so dont quote me on that.