I have duel cats on my 96 GMC I want to take them off how can I do that with the 02 sensors being before and after the cats

 

why remove the cats? They can be cleaned , also, you could end up with chronic check engine light. are you sure its worth it?

 

Well if I can clean them even better how do I do that

 

You have 2 choices, first, you could try lacquer thinner in the fuel tank. this is an easy try. the ratio is 1 gallon thinner to 9 gallons of gas. If you have questions about doing this, go watch the video about it at scottykilmer.com. also, you could remove them and soak them for several hours or overnight in a household detergent and water bath. If you do opt for the thinner in the gas deal, you will have to drive the car for a couple of hours at highway speeds for it to do any good. I would definately watch that vid. good luck.