What purpose does disabling the O2 sensors server? It's my understanding that if you take off the cats, the check engine light will turn on and disabling the sensors will make that light turn off.
Does it do anything else? Like during inspection, will the computer report that something is wrong? Or will the inspector only know if he hooks up the sniffer to the tailpipe?

 

pretty sure they are only to monitor the functionality of the cats. if you have them turned off or put MIL's on there the computer just thinks everthing is okay. can't say much as far as inspection goes, never had one...