What is it?

Your car's emission system keeps the engine running cleanly and efficiently in all sorts of operating conditions. A steady or flashing warning light on your vehicle dashboard indicates a problem that is currently happening and may require immediate attention. Failure to do so can reduce your gas mileage or cause your vehicle to pollute.

What does it do?

Your car's emission system controls the emissions, exhaust and pollutants (including gasoline vapors escaping from the fuel tank), using an array of sensors, computerized engine controls and the exhaust components. The emission system substantially reduces harmful gases such as carbon monoxide (CO), unburned hydrocarbons (HC) and oxides of nitrogen (NOx) and, by law, must be maintained in operating condition.

Typical Wear and Tear

Some factors affecting the emission system include:

• Driving and atmospheric conditions

• Mileage

• Vehicle age

• Type of spark plug electrode material

• Poor vehicle maintenance

• Poor quality fuel

• Damaged or worn sensors

• Dry-rotted or cracked vacuum hoses