While on the emission dyno, my results change drasticly between tests. My first run on HC was 12.00, second was 7.10, third was 2.96, and my fourth was 9.43. Why is it so different every run? I did a full tune up after the second run and i did nothing different between the third and fourth run. My limit BTW is 1.4 for HC. The rest of the tests stay the same for every run. I really need to get plates on my bird.

 

this might have been due to the changing temperatures of your car. running a car hot will lower your emmisions

 

Heating up the cat good will make it run cleaner... Might want to check your timing to lower those numbers. Saw a truck today that pegged the smog machine cause it was too far advanced. Back to stock timing the HC went way down.