Help where is the o2 sensor located

I have a 2001 kia sportage limited and need to replace the o2 sensor can someone tell me where its located in the engine area...... And better yer is someone has a link w a diagram to show me ...thank you

There a 2 sensors, one just at exit of exhaust manifold, the other after the pre-cat.
Register at www.kiatechinfo.com for all the diagrams you want.