First off, know that by removing your cats, your truck will not pass emissions testing. But if you want to remove your cats, or you have already, here is how to trick the rear 02 sensors, so that you don't need to reprogram the ECM. click the web sight and you can order these,
http://www.bigdaddiesgarage.com/mini-cat-cel-fix.html or you can do what I did and build your own. I used 4 sparkplug non foulers. I took the honey comb that I removed from my cats. I used a hack saw, and a bench grinder to make the honey comb fit into the spark plug non fouler. If you do this, use a dust mask, or even better a respirator, grinding the honey comb makes a lot of dust. Also if you pull the hack saw to ruff cut the honey comb, it works better. If you try to push the saw, its to aggressive, and the honey comb is brittle.The little pieces of honey comb you need, will need to fit between the 02 sensor and the non fouler, that is next to the exhaust pipe, inside the non fouler, it will look like the pic on the web sight where you can buy them. They will need to be about 1/2 thick, and need to fit just slightly loose. You don't want to crush the honey comb when you put the 2 non foulers together. It will crumble and not work. Also be sure that the honey comb is not clogged up. I just used my breath to blow the honey comb clean once I got it to fit inside the non fouler. This gives the rear 02 sensor what it is looking for, it thinks there is still a cat.