Originally Posted by Jigga JJ

well most likely its your cat. You just passed on your hydrocarbon readings. If you replae your cat your HC readings should decrease as well. And make sure you have enough coolant in your system. Lack of coolant will cause your NOX to go high as well. Another thing is to make sure your EGR valve is functioning properly. If you have to remove it and clean it out. And make sure the ports are clean as well. Most hondas fail nox becuase of the EGR valve. So serivice the EGR for sure. Possibly the cat. The last thing to keep in mind is, if you are burning oil it will cause your cat to go bad becasue the oil that comes from the engine will foul your catalytic converter. Thus causing your HC's to rise.

Originally Posted by ED9man

I don't think there's an EGR on the B16a.

Originally Posted by petrosvr4

No EGR on my B16A