I've not done it yet but I found this web page with instructions. http://egt.gwebworks.com/garage2.shtml
how to replace a knock sensor on a 2002 hyundai elantra
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.
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..
The 2002 Hyundai Elantra has 43.2 in. of front leg room.