One problem related to sway bar has been reported for the 2003 Hyundai Elantra. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2003 Hyundai Elantra based on all problems reported for the 2003 Elantra.
I was driving downhill to a stop sign (from about 20mph), and pressed the brake pedal, at which point I heard an awful crunch noise, and the front right corner of my car jolted, shook, and sounded like something was grinding together. I got out of the car to look at the front right wheel, and saw that it was turned in towards the center of the car, and bent under the front of the car, about 1/4" away from the back of the wheel well, while my other front wheel was aimed straight ahead. I drove the car 100 feet to a safe place off the street, during which trip the steering wheel tried to spin wildly in various directions, and the crunching, jolting noises and motions continued. The car was not drivable, so I called a flatbed tow truck, who towed it to my mechanic. . When the mechanic was able to look at the vehicle, he determined that the control arm had completely snapped in half, as a result of rust corrosion from the inside out. Visual inspection of the control arm confirmed that the metal it is constructed out of was corroded down to a thickness of approximately 5 or 6 sheets of paper. Water kicked up from wet roads by the tires had gotten inside the control arm (through a faulty seal) and, as there are no drainage holes in the control arm, it remained inside, eating away at the metal until finally the weight of the car snapped the arm in half. This failure of the control arm also wrecked the suspension of the car, as well as the cv shaft, the right front axle, and the sway bar links. The control arm, the cv shaft, and the sway bar links had to be completely replaced, and the car needed a realignment.