The oxygen sensor on your vehicle is instrumental in measuring how much oxygen is in the exhaust and reporting that information back to the electronic control module. The sensor sends a volt to the module that the module translates into the proper mixture to send to the engine. The sensor monitors the catalytic converter to ensure that it is functioning. The measurement determines whether or not your air to fuel mixture is too lean or too rich.
A rich mixture means there is not enough oxygen in the mix, so the fuel does not completely burn off after the combustion. If there is too much oxygen in the mix, the fuel burns too quickly. Both of these are damaging to the engine. Ideally, you want all of the fuel to burn off when it combusts.
Since the mixture is ever-changing as you drive based on factors like acceleration or engine temperature, the oxygen sensor must be in good working condition so that the control module can make real-time adjustments to the engine’s timing and fuel delivery. This keeps your engine at peak performance.
HOW LONG DO THEY LAST?
Your vehicle may have one or more O2 sensors in it, depending upon the year it was manufactured and the engine configuration. A V6 and V8 engine may have three sensors, while a 4-cylinder may only have two.
No matter how many you have, the life expectancy of the sensor is limited. If the car was manufactured in the 1980s or 1990s, you might get 60,000 miles from the sensor. Newer cars put the life expectancy closer to 100,000 miles.
SIGNS OF A FAILING O2 SENSOR
As the O2 sensor fails, you may notice it in several ways. Here are just a few of them:
- Poor fuel mileage
- Check engine light comes on and does not go off
- Rough engine performance
- Black smoke from the tailpipe
- Fouled spark plugs
- Failing your emission check
If you notice these problems after you have done a tune-up and changed the plugs and plug wires, you may have a faulty O2 sensor. The spark plugs get very clogged up when the air to fuel mixture is incorrect.
The best way to diagnose the problem is to take it to a professional technician because they have the proper tools to get the diagnostic code from the engine and can give you the results quickly.
