ev0lution9

iTrader: (3)

i did my research and everything about it how to fix i have a question about my cat back exhaust though...i am pretty sure my 2nd o2 sensor is located just after the cat but ive heard that its located on the test pipe? i know my test pipe had the opening for it but not sure about the sensor i am about to go fix it and i do have the anti-fouler. any tips would be really appreciated, thanks!