I failed the NJ test my readings are:

Standard Result
937 178 NOx
124 352 HC ( this is the fail)
.69 .34 CO%


What could cause the high HC count?

 

I had the same problem this year, it was due to a bad "High flow Cat". The thing was only a year old but I changed it out to a "Stock" one and passed with flying colors. The guy who installed both cats for me said that in his experience the high flows tend to only last a couple of years. There is much less material in them and they are more prone to burn out and physical (insides breaking) failure. Since it was only a year for me he only charged me for the difference in cost because the "Stock" one was $40 more.

Good luck

 

I don't think it would be the cat because it is brand new (installed by a shop in late June of this year). I had a load of bad gas a few months back and she has had a bit of a rough idle, so it might be fuel fouled plugs, I am about to check them. Anyone else?

 

egr