[CateraMV6]

I will have a look in my Service Manual and get back to you... otherwise the NO refers to NOX emissions correct? those are related to combustion so I would say something with the fuel mixture is messed up so the car is messing things up...

Could be ambient air temperature, Mass Air Flow sensor, O2 Sensors... or even coolant temp sensor... something is messing with the fuel mixture and I am guessing that its making it too lean and thus the low production of the other CO, and HCppm, but that results in increased NO emissions...

Now I am hoping someone else will correct me but thats my initial thought...

I will get back to you with my findings...