Check Engine Light On problems of the 2011 Hyundai Accent

I brought my car into the dealership at 33000 miles when it was bucking and hesitating when I accelerated. The mechanic could not detect a code and told me to drive the vehicle until the part completely broke down and a check engine light came on. The car soon would not accelerate past 25 mph and was bucking up and down like a ping pong ball. I crawled into the dealership and was told I needed an ignition coil replaced. I was also told the other coils would probably go bad one by one, but I couldn't have them all replaced under the warranty at one time until they malfunctioned. I was very nervous driving the car until in December 2014 another coil started occasionally to act up. On some days the car will buck and hesitate for a few minutes, but the check engine light will not come on, so when I bring the car in to the dealership, they cannot find anything wrong and the problem cannot be duplicated. On other days the problem is very mild and only for a few seconds and still the check engine light does not come on. When I had the problem severely one day, I drove to another mechanic in a chain repair facility and they put the car on a master computer which detected a problem in the #4 ignition coil. They suggested I race over to the dealership to see if they could catch the problem also on their master computer, but they could not detect anything. I want the #4 ignition coil replaced under the warranty because I am a senior citizen and am very nervous driving my car around in this broken condition. The main problem is that the check engine light does not come on and there is no code stored. My daughter has the same problem with her 2011 Hyundai Accent. I hesitate driving my car the hour to visit my son for fear I will suddenly need a tow in an unfamiliar neighborhood. The number of complaints here for this same problem warrants a recall.