Geez your HC count is quite high...good lord. Cat or 02 sensors could be the culprit (but interesting that you say no CHECK ENGINE light) time to whip out the old multimeter and get readings between terminals on the O2 sensor and check and compare to factory specs (i can look them up for you tonight if you want) ...I don't want to give you exact ideas as i haven't taken a smog course yet, do you have EGR valves? Are they somehow unhooked, clogged, etc...yes a friend of mine had his egr valves somehow unhooked that's why I threw that out. How about your intake, is it clean? Check by removing the plenum tubing and try cleaning out your Throttle body. How about your PVC valve (atop the valve cover), take that out, shake it, and see if it rattles (by the way it's supposed to rattle, if it doesn't it might be clogged). These as starting points, but the SMOG techs here can give you better advice.