Your vehicle's oxygen sensor measures the level of oxygen in the exhaust from the engine. This information is used by the Power-train Control Module (PCM) to determine the correct air / fuel ratio for your engine in real time. The sensor is located in the exhaust system and allows the fuel injection and engine stall to operate efficiently, making it easier to control emissions. The oxygen sensor transmits the data to the vehicle's PCM to maintain the optimum air / fuel ratio for your engine. A defective or failed oxygen sensor will have a negative impact on environmental emissions and engine performance.
There are 3 things to watch for before your oxygen sensor fails completely.

1.
Check that the engine warning light comes on

The first line of defense is the Check Engine witness. The engine check light will come on if your oxygen sensor is faulty. As soon as
this light comes on, contact a professional automotive technician for a check engine inspection. This light can come on for different reasons. It is therefore important to have it examined by a professional who can correctly diagnose the exact cause. If your vehicle has a high mileage, there is a good chance that its defective oxygen sensor needs to be replaced.

2.
Bad fuel consumption and smell of rotten eggs

If the oxygen sensor goes bad, the fuel supply and fuel combustion systems will be ejected. If a bad oxygen sensor interferes with the air / fuel mixture or if too much fuel is injected into the engine, the fuel consumption of your vehicle will be reduced. This excess fuel in the engine can give off a smell of rotten egg, sulfuric, or even black smoke. If you fill your fuel tank more often, note how many gallons you fill and how often. If it's more than normal, ask a professional mechanic to check your oxygen sensor.

3.
Engine idling and misfires

When your oxygen sensor goes bad, you may notice that your vehicle is in poor condition, is burning poorly, or is idling slowly. You may also notice other engine performance problems, such as loss of power, hesitation, or stall. Since the oxygen sensor output controls engine timing, combustion intervals, and air / fuel ratio, a faulty sensor can disrupt these engine functions, resulting in an irregular engine idle and other problems related to the engine.

POINTS TO NOTE:
If your vehicle has been manufactured in the last 15 years, the oxygen sensor must be replaced every 60,000 to 90,000 miles. This sensor wears out and will need to be replaced over time. Replacing a faulty or defective oxygen sensor will reduce the level of emissions your vehicle releases into the atmosphere while keeping the engine running smoothly and properly. As soon as you notice that your Check Engine Light, low gas mileage, or irregular engine idle, make an appointment to replace your oxygen sensor. This will ensure the proper functioning and efficiency of your vehicle and help extend the life of your engine.
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