Scott.gregory.clark

I have a check engine code reading that suggests I need to replace the 02 sensor in position, bank one sensor one. I can only find only find one o2 sensor forward of or upstream right after the catalytic converter. Does anyone have an image of where bank one sensor one would be or who can confirm there is only one o2 sensor upstream or in front of the catalytic converter? I ask because I've replaced the one I could find and still have the check engine light. Thanks!