[Underpowered]

if you take them out, your CEL will come on. to solve that you have to have your rear O2 sensors turned off in your computer via a tune. or buy some O2 simulators that will always send a good signal to the PCM.

how much did it cost to have the one replaced? i know when mine went bad shops wanted an outrageous price to replace them. $300 each to buy and install the cats. Personally i would say keep em. they help if you ever plan on getting rid of the truck, as most dealers will not take it in on trade if they are removed.