Nasty Hawk

I have a 2002 TA M6 with all mods listed below. I have slp lt's with cats. My car keeps throwing an 02 sensor code. (The rears are deleted) I would reset the code and it would be good for a couple days then come back and foul my idle up, but i would drive it like that for a week and it would go away for a little while then come back. i replaced the front 02's with the rears wich i know were good and same thing???????????????? please help!!! what should i do.............

family sedan

iTrader: (3)

If you have catalytic converters why not just undelete the o2 codes and put all 4 o2's in and let it function properly?