Well, we all know the cat can be lazy, however if it failing completely then you would have a CEL. You would also have a CEL if the 02 sensors were bad. These don't get lazy, they work or they don't. I do not think it is the ITR cams since the smog dyno does not even take the rpms up high enough to engage the changeover point. However, if the valve adjustment was not done to full spec. the motor may not be running right. High HC means that "all" hydrocarbons within required spec. are not being burned off. So stop looking for the stuff w/no CEL's. If you have not already done so, I would adjust the valves, do a full tune up and run a honda top end cleaner through and see where you are. Have you ever used race fuel? Just asking...