How much does it cost to replace an O2 sensor?

READ CAREFULLY HERE! IF the CHECK ENGINE system is POINTING to the O2 sensor it does NOT necessarily mean that you need a NEW SENSOR! It is going OUT of RANGE probably! BELIEVE it or NOT, it is ALL ABOUT your OIL CHOICES and if the AIR/FUEL ixture is within specs!>>>DO THIS FIRST! Go to any AUTO STORE that carries CATACLEAN FOLLOW DIRECTIONS! If you EVER used VALVOLINE OIL STOP AT ONCE! Your car REQUIRE a GREAT synthetic that has the HYUNDAI approval ratings! TRY using PENNZOIL ULTRA PLATINUM that gives a 500,000 mile extended ENGINE WARRANTY! It takes away LOTS of WORRTING! If you are NOT CAR SAVVY find someone that is willing to clean your IDLE AIR CONTROL VALVE and THROTTLE BODY and KNOWS to use AMSOIL POWER FOAM to do this! POWER WASH the ENGINE BAY using GUNK ORANGE and change the PENNZOIL when it becomes DARK BROWN proving that it is doing it's JOB< which is to CLEAN away the OLD OIL residues left behind! RUNNING AMSOIL POWER FOAM through the PCV and INTAKE SYSTEM will restore the PISTON RINGS to BRAND NEW! These things will CLEAN THE o2 SENSORS for you and the LIGHT will go OFF! NEVER USE WAX BASED CHEAP OILS! You have a WINNING CAR here, and it has SPECIAL NEEDS! At 100,000 miles change ALL THE FLUIDS, even the BRAKE FLUID with HYUNDAI FLUIDS! Go ANOTHER 100,000 miles! Use MICHELIN HARMONY TIRES or other GREEN TIRES to save on GAS and get the HIGHEST tire warranty!  The ASIANS are AMAZING and they almost ALWAYS have the HIGHEST RATING!  BECAUSE it is a GENESIS they are SPICING up the pricing! TURN THEM into the BETTER BUSINESS BUREAU! There is NO O@ sensor or AIRS of them that are THAT OUTRAGEOUS! Use your conputer and go teo ROCK AUTO to see the REAL costs involoved! If you DO need one or two ( AND I DOUBT IT) use BOSCH ones! They WROTE th book on this technology! RIOCK AUTO generaly cannot be BEATEN with prices for your car or ANY CAR! AND AGAIN< your current ones are TELLING YOU YOU NEED TO PROEPRLY TUNE THIS THING! Use new DENSO TWIN TIP IRIDIUM lASER PLUGS that get the BEST power and mielage and PRIOTECT your O@ sensors frmo FAILING! BYE NOW! 

I would ask for them to break down the quote for you.  Even an OEM oxygen sensor on high end vehicles isn't that much.  They must be doing something else as well.

If they are quoting only an oxygen sensor, take your car elsewhere.

$1,200 can buy many O2 sensors. If you can do it yourself, I bet you would not ask this question. So, I think the cost is 4-5 times the O2 sensor itself. I would say, if an O2 sensor costs $50, then the total maybe around $200. Or $400 is for worst case. But, different people have different ways of spending their money. Replacing O2 sensor is a very simple job, you can do it if you try.

Call AutoZone or Oreilley, etc and get a price for the O₂ sensor.  Mine was $35.  I think your mechanic is tired of working for a living. 

Maybe it costs $100.  $50 labor should cover it.  I'm not a Korean car expert, so I don't have costs in my head.

That's higher than balls on a giraffe. 

For $1200 they are replacing most of the exhaust system. 02 sensors cost around $100 each and an hour labor to install them.

Is this a serious question? $1200 to replace one (1) 02 sensor, where did you take the car to? $200 would be high priced, go someplace else.

Another Hyundai spam.  Please report.

Yes, it's outrageous.  The part itself is about $50, just like for any other car.  I would ask them WHY it's so much, and see what they say.

Check this out - https://www.yourmechanic.com/estimates/hyundai/gen...

Seems a bit high, like $800 too much but contact them for a quote.