Massachusetts Vehicle Check - Mass08 Management Module ...

Non-Commercial
Carbon Monoxide
Carbon Monoxide (CO) is a colorless, odorless, and poisonous
gas, produced by incomplete burning of a fuel. CO is formed when
there is not enough oxygen to support combustion. When carbon
monoxide gets into the body, it prevents the blood from bringing oxygen
to cells, tissues, and organs.
High levels of Carbon Monoxide (CO) can cause injury or even death. Excessive CO
emissions can be caused by a rich air-fuel mixture, a dirty air filter, faulty injectors, high fuel
pressures, defective system input sensors, plugged Positive Crankcase Ventilation (PCV),
stuck open heat riser valve, Air Injection Reaction (AIR) pump malfunctions or engine oil
diluted with gasoline.
Nitrogen Oxides
Nitrogen oxides (collectively called NOx) are formed in vehicle
engines during the combustion of fuel at high temperatures. When
nitrogen oxides are combined with hydrocarbons and exposed to
sunlight, smog is created. Most NOx originates from automobiles. As
anyone who has taken a walk in a smoggy city would know, the short
term effects of NOx are irritation of the eyes, nose, and throat. Prolonged exposure to the
pollutant can cause permanent respiratory problems, such as asthma. Excessive NOx
emissions can be caused by a lean air-fuel mixture, defective Exhaust Gas Recirculation
(EGR), higher than normal engine temperatures, vacuum leaks or advanced ignition timing.
Massachusetts Vehicle Check
Ch. 1 - 4