Could be many things. First make sure that when you replace them that you don't touch the bulb with your fingers. Even the slightest bit of oil can cause the bulb to overheat and blow. Second make sure the lens assembly isn't cracked or damaged and moisture isn't getting into the area. Third make sure you're replacing the bulbs with the proper replacement and that you don't get them from a discount store.
Did you check the fuses?
The 2002 Hyundai Elantra has 16 valves.
The 2002 Hyundai Elantra has a 5-speed manual.
The 2002 Hyundai Elantra is a gas-powered vehicle.
The 2002 Hyundai Elantra has an inline 4 engine.
The 2002 Hyundai Elantra has double overhead cam (DOHC).
The height of the 2002 Hyundai Elantra is 4 ft. 8.1 in. (56.1 in.).
The 2002 Hyundai Elantra is 14 ft. 9.1 in. (177.1 in.) long.
how to replace a knock sensor on a 2002 hyundai elantra
The curb weight of the 2002 Hyundai Elantra is 2635 lbs..
The 2002 Hyundai Elantra runs on regular unleaded.
The 2002 Hyundai Elantra's turning circle is 37.5 ft..