The "SMOG pump" (AIR system) pumps air into the exhause manifold in an attempt to reduce HC @ idle speed. The injection point is near the ex. valve & may have a 'cooling effect' (of sorts) at idle only.
This stiring up/dillution of HC @ idle creates a lower reading during the test procedure as it "fools" the meter.
At 'run speeds' it robs horsepower and fuel mileage which is the oposite of cleaning the air because fuel is waisted.
The cost of it is a financial disaster too. Just think of a $100+ cost (per unit) times the # of cars made in the USA and eslewhere.
In addition: There's no way anyone can do any type of (objective) research on this situation as It's illegal to remove or alter the devices.
The games "rigged" by the government here.
Most states (the other 49) just do what the EPA says which is okay, as most vehicles will pass the test with their standards W/O the "devices". Especially those with EFI/HEI systems that are 'joined' via computer.
The really 'scarey' part is many believe the government after 45+ years of SMOG propaganda. Prop 87 almost passed due to it.
Thank GOD for almost.
