Malfunction emissions control light on

I have a 2011 elantra with 22k and the car has been in the shop 4 times for the check engine light. They replaced th o2 sensors, but still coming on. The dealership was told to stop working on it and a tech from Hyundai corp. was going I fly in. Apparently they are having similar troubles with other cars, primarily on the east coast. They tried to blame it on bad gas in the region. Who knows. Good luck.

I have a 2007 Sonata and the check engine light came on right after I bought it. They turned the light off and told me it was nothing. Over the years the light has been on and off on occasions. The last time it was on, I brought it in and they replaced one of the 02 sensors, $275. Less than 2 weeks later the check engine light was on again. I returned to the dealer and they told me it was another 02 sensor which would cost another $275. I said, no way am I paying again. The car had 41,000 miles and had just gone out of warranty 2 weeks prior. The fixed the car with no charge to me. I'm afraid the light will go on again because I'm not really sure they know why it's going on.