Hi, i brought a 2006 k12 a little while ago as a little run around, the engine management light came on the other day, i plugged it in and the fault code was P1035. That apparently is catalytic converter/front nox sensor, so i have been looking online for a nox sensor and all i can find for a k12 is the lambda sensor, having driven diesels for years i am a bit confused, I'm sure they're 2 different things, any help would be greatly appreciated.