im 99% sure the ractive is bolt in, all you need is a MIL if you wanna avoid a CEL, but if you wanna do it right you want to get a o2 sensor bung behind the 2nd cat and exetnd your 02 sensor wire.
i wrote about it before, i feel the MIL is a bad idea as it makes the computer run randomly rich (the o2 sensor controls the a/f ratio) i know my car ran pig rich with an MIL (70 miles to 1 tank)