Replace the catalytic converter with the decat pipe

[TomiEling]

Hi folks
i have Clio 1.8i 16V, 1993.
I want to replace the catalytic converter with the decat pipe that i found on ebay:
http://cgi.ebay.com/RENAULT-CLIO-MK1...85889442698475

But, the thing that bother me is the Lambda (O2) sensor. In my case there is only one sensor. As i reed on the other forums, people says that replacement of the catalytic converter with the decat pipe do not require modifications of the O2 sensor, just simple replacement of the catalytic with the pipe. But some other peoples say that after replacement you should do a "remap" of the O2 sensor.
Is there anyone who have experience with this case?
Thank you.
Best Regards