One problem related to o2 sensor has been reported for the 1996 Hyundai Elantra. The most recently reported issues are listed below.
Consumer states while driving, the engine check light came on and then the vehicle stalled out. Vehicle has been to the dealer on several occasions and the problem is reccurring. Oxygen sensor and coil pack were replaced. Fuel injectors were cleaned, throttle body replaced. But problem still existed until dealer found battery had dead cell.