Apr 22 2009
If you are concerned about your car's carbon footprint, it's important to know that your vehicle's O2 sensor (oxygen sensor) plays a key role in sounding the alarm if excessive harmful exhaust emissions are coming out the tailpipe.
"A properly functioning O2 sensor plays the role of a watchdog when it comes to monitoring your car's exhaust emissions, especially hydrocarbons and carbon monoxide," said Warren Suter, Director, Engine Management Systems for Bosch, which developed the automotive oxygen sensor in 1976. Bosch is the world's largest supplier of automotive parts and systems.
The O2 sensor measures the oxygen in the exhaust and signals the engine's computer to adjust the air-fuel ratio to ensure that combustion is as complete as possible. This continuous process optimizes engine performance and fuel efficiency and reduces harmful emissions. A vehicle, depending on the make, model and year, can have between one and four O2 sensors at various locations in the exhaust stream.
If an O2 sensor is worn out and fails to assess the air-fuel ratio accurately, the engine's computer tries to accommodate the perceived variation and, in the process, may adjust the mixture to be too lean or too rich. The result? Harmful tailpipe emissions and possible damage to the catalytic converter and other engine components.
O2 sensors of course, are built to last. In fact, many still function perfectly with 100,000 miles on them. However, the daily extreme thermal shock, vibration, and other factors can cause O2 sensors to wear out sooner than their normal life expectancy. Also, they can become sluggish with age, and a worn out sensor is often the cause of failure to pass an emissions test during an inspection.
As a result, O2 sensors should be replaced once they wear out - or when they have so many miles on them they are likely to wear out soon. Bosch, which offers the industry's most comprehensive line of oxygen sensors for both original equipment and the aftermarket, recommends checking the sensors regularly to maintain vehicle efficiency.
"A properly functioning O2 sensor on your vehicle can do more for the environment than you realize," Suter said.