Yeah, I hear ya, i feel the same, but, I'm still young, and I love working on cars, so I wanna carry on with it for a bit. Ok, I checked the readings on the sheet again, and it turns out its not NOx, its HC. So that would point out a bad cat. I'm gonna call my piping/cat place tomorrow, because apparently they have updates for the exhaust, and instead of 3 cats, it's going to be only one, with slots for the O2 sensors.