decats

I'm thinking of going decat but I've just searched and found it brings a fault up, will the car run rough with the fault code or will it be fine and its just a case of erasing it every now and again?

i want to know people with decats, who fitted foulers on the post o2 sensor. How many miles do these last? ive order some rockautos. i want the fault resistance too high to disappear.

I've spotted 2 different types of downpipe and de-cat systems going on ebay and was wondering if anyone has bought these and if they are any good? Having 2 lambda sensors a guess the 2nd one would be a better option.... unless they are both a pile of doo-doo.....? Also, anyone know of...