NOx too high

[bksimms]

I had a state emissions test ran today and my vehicle failed. The NOx standard is 956 and mine ran 2725. What can cause this. I also had the check engine light on and had the code checked at autozone and it said the intake air temp sensor was the fault. Replaced it and light still comes on. Had code rechecked and it is still there. Unhooked battery and still cant get it to clear. Need help on this nox so I can get inspected.

 

[Alec]

The air intake temp code comes up often instead of other codes. Don't ask me why. I'm guessing your cats are failing and not doing their job of helping emmissions. But it could also be that you're running rich. Are you noticing any smells, smoke, etc from the exhaust?

 

[bksimms]

Not getting any smoke or smells. All other test for emissions are good

 

[mrboyle]

High NOx is usually related to the cats on a Ford. Their 2-cat system uses a "pre-cat" and a "NOx cat." The second cat is designed specifically to help reduce NOx levels. If is bad the NOx levels will skyrocket. If all the other gasses were within spec I would suspect the rear cat.