Originally Posted by RamTech
Your truck has 4 O2 sensors. I'm surprised you don't have a MIL lamp on with a rattling cat at this point. Hollowing out the cat's may provide a minor performance increase but I doubt you'll hear a big difference in the exhaust tone. Gutting the cats can cause a MIL to come on but there are ways to fool the PCM into thinking it's there.
Thanks for the info, now if the 02 sensors are prior to the Cat then how will it throw the the code? My main focus is to just reduce the rattle at this point. Some people have said removing the cat increased fuel mileage but I think its most likely negligible.