Although you've probably heard the term "oxygen sensor" before, you may not know what it is or why you need one. This component is one of the most important sensors in your vehicle and helps maintain engine performance and environmental safety.
Keep reading to learn how an oxygen sensor works, the symptoms of a faulty oxygen sensor, and why it's a bad idea to drive with a bad O2 sensor.
What does an oxygen sensor do?
O2 sensors measure the oxygen level in your exhaust gases to measure the 'efficiency' of the engine.
Gas engines work by burning an air-fuel mixture in the engine's cylinders. This mixture must be burned in a precise ratio to work most efficiently. If this ratio is incorrect, the mixture in the engine is considered 'rich' if there is not enough oxygen in the mixture, or 'lean' if there is too much oxygen. Both can cause harmful emissions and possibly damage your engine.
The oxygen sensor detects rich or lean mixtures and tells your Powertrain Control Module (PCM) to adjust the ratio. The PCM will then inject more or less fuel into the engine.
Many standard cars come with at least two oxygen sensors. The second sensor also measures the oxygen in the exhaust stream, but only after the exhaust gases have passed the catalytic converter. Catalytic converters convert certain unwanted exhaust gases to help control toxic emissions. This second O2 sensor is located downstream of the catalytic converter and measures how efficiently it converts the exhaust gases.
Oxygen sensor: how it works
Most oxygen sensors generate an electrical signal that tells your car's powertrain control module how much to change the air-fuel mixture. To do this, each sensor continuously measures the oxygen level in the exhaust gas stream and compares it with the oxygen level in the outside air.
Oxygen sensors are usually mounted directly on the exhaust pipe. One part of the O2 sensor is placed in the hot exhaust gas stream, while the other part is in contact with the outside air. The difference in oxygen levels between these two parts causes a chemical reaction that produces a low voltage between 0.1 and 0.9 volts. A value above 0.45 volts indicates that the fuel is burning richly, while a value below 0.45 indicates that the fuel is lean.
Symptoms of a failing oxygen sensor
Oxygen sensors are not components that require regular maintenance or replacement, like brake pads or engine oil. They typically last between 30,000 and 100,000 miles and need to be replaced as soon as they break down. When your oxygen sensor malfunctions, it's only a matter of time before you start experiencing some of the symptoms below:
Illuminated indicator light
Although onecheck the engine lightcan indicate many different problems, with a faulty O2 sensor being one of the most common triggers. As soon as a warning light appears on your dashboard,make an appointmentat your local Firestone Complete Auto Care for engine diagnostic service. If you drive a vehicle with high mileage, chances are the oxygen sensor is to blame.
But several other common failed mechanical or electrical components can lead to too much or too little air or fuel. So let a professional diagnose the cause instead of just replacing an O2 sensor.
Poor gas mileage (plus bad odors and black smoke)
When an oxygen sensor fails, your car can compensate by injecting more fuel into the engine. This not only leads to wasted fuel and fuelpoor fuel consumption, but it can also result in several unpleasant side effects. If too much unburned fuel is left in the engine, it can develop a rotten egg smell and even black smoke coming from the exhaust. In some cases, the unburned fuel can overheat your catalytic converter.
Keep track of how often you fill up your gas tank and watch for black smoke coming from the exhaust. If a bad O2 sensor is the cause, you may fail the emissions test during your next MOT.
Poor engine performance
Will a bad O2 sensor cause hard idling and loss of engine power? You can believe that. Additionally, you may also notice poor acceleration, engine misfiring, and even stalling. Bad oxygen sensors disrupt a variety of essential engine functions, including engine timing, combustion intervals and air-fuel ratios.
If you notice that your engine is not working properly, do not wait to bring your car ininspection. It is much cheaper to replace an oxygen sensor than an engine.
Can you drive with a bad oxygen sensor?
The short answer is "Yes", your vehicle's engine can operate without oxygen sensors. But without these, your PCM won't know how much fuel to inject into the engine. Depending on how it goes wrong, you could end up with an overly rich fuel mixture, which will drastically reduce fuel economy and clog your catalytic converter with excess, unburned fuel. This excess can be burned in the catalyst, raising its temperature and possibly shortening its life.
Note: It is much cheaper to replace an oxygen sensor than a catalytic converter.
Are oxygen sensors necessary? Yes. While the damage may seem minor at first, the longer you drive with a bad oxygen sensor, the greater the damage. Ultimately, you may experience rough idling, poor acceleration, engine misfires, an illuminated check engine light, and failed emissions tests.
Let us understand your O2 sensor problems
Don't hold your breath waiting for your O2 sensor problems to go away. Leave the technicians with your loved onesFirestone complete car maintenancehelp solve the problem.make an appointmentToday!
