PCV valve might help, you could also try using some seafoam to clear any engine sludge out of the car. Stupid question, but are you driving your car at highway speeds before the test? and is the engine still hot when the test is performed?

 

I think a PVC valve would help out since it's main job is to send the HC in the bottom of the engine back into the intake.


PCV info

BTW: NAPA price is about $8-$10 vs $25+ from Honda.