"post catalytic converter oxygen sensor"

GM service writer called and said I needed a $250 Post Catalytic Converter Oxygen Sensor for my 2001 Chevy Cavalier. I took the car in because the Check Engine light occasionally comes on. The catalytic
converter was replaced in April but not the Post Catalytic Converter Oxygen Sensor. This part was not replaced at that time because it was not showing defective.
Can I just NOT replace the Post Converter Sensor? What can I expect if I do not replace this part?
Thanks
Tim
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Failed emissions test if your state does them.

-
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Not sure how your car handles things, but it could mean that your car runs poorly or that you run too rich and ruin that cat at some point. Why not just get an aftermarket one for much cheaper and install it yourself? They aren't that tough. Should be able to get one for $80 I should think and replace yourself.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.