Might be better to ensure there isn't a real problem. I assume you looked at the cats when you got this error and they aren't glowing red hot. If they are too hot then you need to fix the source of that problem. If they aren't actually too hot, might just be the cat ecu module that needs to be replaced. There is one on the left and right side of the engine bay. Easy and cheap fix with aftermarket part from Technistrada.
I was asking because I bought a Kess programmer and been playing around doing some ECU tunes. I am able to shut down the O2 sensors but havent found anything for bypassing the cat ecu's completely. Once in a while I get the slow down lights only after a cold start and only lasts for 60 seconds then gos away. Fixing the lights as you said can be done easily, just curious if it can be done through the main ecu.
