No, I haven't used any fuel additives. Emissions testing in VA costs $28.00 with a free re-test and is required every 2 years. It was about a 10 minute drive to the station but since there were many cars in line the engine was turned off. I waited in line for over an hour before starting the car for its inspection, so probably it was not fully hot. I would think though, that a tepid cat convertor would affect the NO readings a lot more than the HC readings but I could be wrong. However, the NO readings were well within spec so wouldn't this indicate that it was up to temperature?

Anyway, at the first opportunity, I am going to test the O2 sensor at the connector to make sure that its voltage is fluctuating between .2 and .8 volts.

If the O2 sensor checks out, I will try leaning the mixture ever so slightly since as Matt L. pointed out, there is plenty of room in the NO reading. Thanks.

T.C.