Two weeks ago I got my Dad's old 92 GMC pickup that has been sitting up for some time down to Quick Sticker, where it failed the HC portion of the emissions test with a reading of 162 ppm over the standard of 143 ppm. Of course I had just filled the 26 gallon tank with fresh gas and with both stickers expired over two years ago, it didn't seem likely I would be able to drive all that gas out. I managed to siphon out about half a tank (cough, spit, gag) a skill I have apparently lost over the years.
The kid at Quick Sticker had recommended RXP, but I've always been a skeptic of that and any other "mechanic in a bottle", but here it was, my last day for a free retest and I didn't have the time to do it properly, (run a full tank, replace with fresh gas, change oil) so I just let it run in the driveway for about an hour with the gas pedal scotched down to burn some through.
Drove back, and he put it on the treadmill. It passed with 125 ppm this time. It also dropped the Nox as well from 326 to 317, but that was already within legal limits.::Banana::
Best $6.99 I have ever spent!