Cat removal
 

I have just removed the Cat from my R1150GS and fitted a remus Y piece. After asking a number of people I have also disconnected the oxygen sensor that was previously inserted into the Cat. The bike now runs smoother than it did before but it does back fire on the overun which i guess means that it is running rich. I have run this by a number of people and in the main they say that this is normal and that no undue damage will be caused.

Does anyone have any views on whether to leave the oxygen sensor out or should I re connect it?

Any help appreciated.