Does anyone know if the check engine light or any codes will come up if I remove two (rear) of the four cats on my 00 5.4?

 

This would be an application for the MIL / O2 simulators.

Removing the second set of cats, would make the downstream HO2S think that somethng is wrong. Installing the simulators would take care of this.

The brand that I am aware of is Casper Electronics, but I am sure there are others that you can get to do the same thing.

 

thanks