Hyundai Repair: 1999 hyndai elantra, crankshaft sensor, hyndai

Question
just put in new crankshaft sensor and car is running fine but the check engine light is still on.  

Answer
If you checked the codes prior to repair and the only trouble codes present were for the crankshaft sensor, and if you haven't yet cleared the codes, disconnect the battery for five seconds to clear the codes.

If you didn't check the codes prior to repair, or you cleared the codes and the lamp came back, you should reread the diagnostic trouble codes.  This will allow us to know what sort of abnormality the computer is seeing.