So I’m first time Hyundai owner. Got my 2018 SEL in October. All was good at first but within two weeks started feeling the engine becoming quite sputtery during times of accelerating and braking and my gas mileage had been going down, then finally my check engine light came on. Took the car into the dealership, they said it was a code in the computer causing the engine to misfire and that they had corrected it. Car felt pretty good after that but now my gas mileage has been going down again and still feeling the engine is jumpy during acceleration and decleration. Check engine light however has not come back on. Is this something worth taking the car back to the dealership or no? Anyone else have any similar issues with 2018 Elantras?