Another MIL Eliminator & reset codes Question

Ok, I tried the solder in MIL E's, cleaned my O2 sensors & reset my check engine light with a code reader. I thought everything was good until after about a week. Now, I am getting both 0430 and 0420 codes.

First question, does it reset the whole computer when I reset the Service Engine light with a code reader? Or does it just clear the codes. Every time I read the codes I just go ahead and reset the light for the heck of it. I am just wondering if the car has to re-learn everything every time I am doing this.

Second question, I am going to try the plug in MIL E's. Should I remove the soldered in MIL E's, or just leave as-is and plug in the new MIL E's. I am thinking I need to remove the soldered in one, but want to make sure.

I am going to be super pi**ed if the plug in ones don't work. Because if they don't, I am going to have to buy a tuner to totally disable them. Anyone know of any shops in the Naples/Ft. Myers area that can disable these for me?

Thanks!

Yes, this is from installing a new exhaust w/o cats. The 0420 and 0430 codes are telling me the cats aren't working correctly. I tried solder in MIL Eliminators, the computer reset, cleared codes with a code scanner, let the car's ECU relearn itself. Still get check engine light. I'm guessing that it is outside the range that even the mil elim's can handle? Although I don't know why or how that would be different on my car than any other. This is why I am skeptical if the plug-in ones are even going to work.