I have a 2013 Hyundai Azera with the 3L V6. I only use 93 octane gas (as recommended) and only use either Shell or Chevron.
Each day, when I get in the car for the first time, I can count on it running rough and having inconsistent performance and some minor sputtering or misfiring (don’t know the difference) until the car gets warm. Once it gets warm, all is well. It has 24k miles. Any thoughts on what may be the root cause? Should I change the fuel filter so soon? Does that matter being it gets better when it warms up?
I change the oil religiously whenever the computer in the car tells me it is time to do so and use Mobil 1 synthetic.
possibly unmetered air
Meaning an intake/exhaust leak after the mass airflow sensor, but before the upstream oxygen sensor
And whatever is leaking . . . flat gasket, for example . . . seals up better when it gets warmed up
Can I assume this car is still under warranty?
If so, it sounds like you need to go to the dealer, and have it fixed, at no charge to you
With only 24k miles, I certainly hope that the car is still under warranty!
If it is still under warranty, then the OP needs to report the symptoms to the dealership and allow them to go through their diagnostic protocol. Even if we give you a possible cause of the problem, the dealership will almost surely ignore that information, and will do their own diagnosis–as is required by the manufacturer.
I can tell you that my brother had similar symptoms with his brand-new Azera, and it turned out to be a defective temperature sensor. However, if you demand that the dealership replace a temp sensor and that turns out to be a blind alley, you will have to pay for that part and the labor to install it. If you allow the dealership to do the diagnosis and repair, your cost should be…zero.
If the dealership is unable to diagnose and fix the problem, then you need to “kick it up a notch” by referring the situation to Hyundai at the corporate level. Contact info can be found in your Owner’s Manual.
A defective temperature sensor was my first thought. But, as the others said, use your warranty. If you try to repair this yourself, or even if you take it to a nondealer shop, you may just void your warranty for any other engine problems that might happen. Follow VDC’s advice.
But… you can always do a cursory look for an air leak and check to see that the temp sensor plug isn’t hanging loose without invalidating your warranty. You might want to do that… but don’t go any farther.