Removed the Catylic Converters

The various "simulators" do not serve to replace a missing rear O2 sensor, but instead filter the signal from a properly functioning sensor to make the ECU believe a cat is installed and functioning.

From the URD product description: "Our rear O2 sensor simulator is a device that conditions the signal from the rear O2 sensor and keeps that signal in the proper range the ECU is expecting to see from a properly functioning and healthy catalytic converter."

They can be easily made for $2 to $3 as described here...

 

Yes, the o2 sims just trick the ecu to make believe the cats are still there and everything is flowing right and within proper levels. I eliminated the rear cats and sensors from my truck entirely.
Having zero worries about these things would be great. Plus being able to live somewhere warm to boot!!