Okay, so last night a friend and i installed a dry nitrous kit on his 2002 GT and so I gave him my autometer air fuel ratio guage. Well, I have installed this type of guage on many turbo charged honda's but never on a four wire O2. The directions are no specific and say not to go directly to the white wires at the o2 but to the o2 signal from the ECM. First of all, where is the ecm ina 2002 stang, and second is it hard to get to? Next thing is where can I get a wiring diagram? Also, on a four wire O2 do I go to both white wires or just the output signal from the ECM? Thanks guys. Oh, can you recommend him any other mustang forums?