Ok so i'm trying to put on my new Injen cat-back exhaust, and the whole exhaust has 3 holes for 3 o2 sensors. Problem is when i get under the car i only see 2, one after the primary Cat Converter, and the the other on further back. Now apparently the 2009 lancers are supposed to have 3 sensors. One in the primary cat and the other ones following. However, i can't find the one that's supposed dto be in the primary cat. Does anyone know if maybe the o2 sensor is position in a way so you can't see it or anyhting like that?? because i got under the car and i didn't see any o2 sensor on the primary cat. Maybe i'm not seeing something, has anyone actually seen all 3 of their o2 sensors on their lancer? (just fyi i don't know if it applies to all lancer trims and models but mine is a 2009 mitsubishi lancer es sport 2.0) also any tips on how to get the primary cat unbolted? because there is no space to work with under there and i can't fit a big enough wrench or ratchet to give me leverage to take out the primary cat bolts. I'm thinking about using an impact gun. Anyway please if anyone know where EXACTLY the first o2 sensor is let me know. the other o2 sensors are easy to see and take out, i'm just having trouble fiding the first one. please help!!!!