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Is it common for 02 sensors to go bad on a car that is less than 2 years old?

hello! I just signed up for this forum which I didn’t know existed so this a great tool thanks to all that respond.
I drive a 2016 Hyundai Azera with 48,000 miles. I travel alot at least 300 miles per week. I take good care of the vehicle (oil changes etc). recently my check engine light came on. I had the car tested twice at O’Reilly Auto Parts and the code P0430 and the second time I had it tested the associate at O’Reilly’s mentioned my O2 sensors are bad. I ran a can of gumout tune up through my gas tank and unplugged my battery to reset the car and the check engine light turned off and stayed off for 4 days. then the light came back on again so I went and got some seafoam motor treatment unplugged the battery again the light remained off all day and just came back on I drove 250 miles today. could it be my 02 sensors? is it difficult to clean the sensors myself? I appreciate any feedback!

No…but it is quite common for people who are not mechanics to declare that O2 sensors are bad when they are working normally. It’s been a problem for years and I don’t see it going away anytime soon.

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It’s possible there’s an o2 sensor problem, but the most likely cause is one of the cats has failed. The cats can be tested for most makes and models, but require a specialized scan tool. They’ll look at the voltage vs time signals from the o2 sensor before the cat and after under different engine conditions. If they don’t match up to spec, you’ll have to replace the cat. That test will spot a faulty o2 sensor too in many cases. Cat failure is unusual in this age of car. It could still be under warranty, so check with the dealership, could save you a bundle. If there are any other codes, deal with them before replacing the cat, because whatever is causing them may be damaging the cat. Except perhaps for oil dripping on the outside of the sensor (the part not in the exhaust stream), O2 sensors cannot be cleaned. They rarely fail at that age, and rarely fail b/c they are dirty, unless work was done on the vehicle which allowed silicone into the exhaust stream somehow, very unlikely as mechanics and auto parts manufacturers are very aware of this problem. Suggest to not monkey with this yourself, as you could void the warranty on the cat.

the OBD scanner showed that it was my 02 sensors that’s why the associate at O’Reilly’s said that. can the problem still be something else? thanks!

thanks I appreciate the feedback I bought the car from CarMax 5 months ago so I’m hoping this problem is covered

This should be covered by Hyundai under the emissions warranty.


The code indicates the catalytic converter isn’t operating properly.

Take the vehicle to the dealer and have catalytic converter replaced under the 8 year/80,000 mile EPA mandated warranty.


that will be my first stop Monday morning… thanks I didn’t know that warranty existed

Unless you purchased an extended warranty the answer is no. Most CarMax vehicles have 30 day warranty, a few states make them have 90 days. This should be spelled out in your paper work.
Also the vehicle manual should tell what is covered for the second owner.

Warranty – The warranty programs are intended to provide effective recourse for consumers against manufacturers when individual vehicles do not meet standards in-use, as well as to deter the manufacture of such vehicles. The section 207(a) warranty is intended to assure that defects in design or workmanship that result in high emissions are remedied. The section 207(b) warranty in certain instances protects from liability, owners who, despite properly, maintaining and using their passenger vehicles or light-duty trucks, fail an EPA-approved Inspection/Maintenance (I/M) test. The 1990 Clean Air Act Amendments established, beginning with the 1995 model year, the warranty for the catalytic converter, electronic control unit, on-board diagnostic device, and other equipment designated by EPA, as a “specific major emission control component” will be 8 years or 80,000 miles; all other emission related parts will be warranted for two years or 24,000 miles. The warranty period for other categories of vehicles and engines are typically established by EPA as part of the standard-setting process.



Also there is a 5 year 60,000 mile powertrain warranty from Hyundai for second owners.


quick update I took my Hyundai to the dealer the cat was bad $974 repair…it was under warranty! thanks for the responses.

Good for you. Thanks for posting the result. There’s a lot of good O2 sensor replaced due to faulty cats.

That is excellent news!
Wouldn’t this be a good time to peruse the warranty booklet in your glove box in order to familiarize yourself with the coverage under all of the car’s various warranties?

OP’s Hyundai was covered by the 5 year 60,000 mile factory warranty and the 8 year 80.000 mile EPA warranty. The 10 year 100,000 mile powertrain warranty does not transfer to subsequent owners. All 3 are explained in the owner’s manual.

this was the aftercat sensor that said cat was not functioning well? newer cats just fail? with a perfectly functioning motor? no oil burning, coolant burning, overly rich mixture and so on? i guess mechanical things do fail so maybe it was a bad cat?

There is also very likely a rust-through warranty.
Every new or new-ish car has several warranties, and every car owner owes it to himself/herself to open the booklet that provides all of the warranty details–and to read those details.