When is it Time to Replace your BMW Oxygen Sensor ?

Positioned at the exhaust area of your car, the BMW oxygen sensor keeps an eye on the amount of oxygen contained by the exhaust gas. It sends a signal to the computer system of your BMW whenever the oxygen and fuel mixture is too rich or too lean. The computer system, subsequently, controls the air and fuel mixture to lessen your BMW’s emissions.

Why is It Important to Avoid Lean and Rich Air-Fuel Mixture?

The BMW oxygen sensor is one of the indispensable automotive components that help execute an effective combustion for your BMW. Combustion is the process of burning gasoline. This is a vital process that enables your vehicle to run efficiently. Oxygen is an element the BMW engine can’t do without. If there is no oxygen, gasoline will not be burned. If there is too little oxygen, the combustion will not be complete. Insufficient amount of oxygen leads to a rich air and fuel mixture, which is definitely a cause of pollution. On the contrary, having too much oxygen in the engine during combustion will bring about a lean mixture of air and fuel. This kind of mixture also negatively affects the operation of the gas engine.

Until When Can the BMW Oxygen Sensor Last?

In the long run, the quality of your BMW oxygen sensor will decrease. Of course, like other auto parts, the oxygen sensor is exposed to impurities resulting from the gas burning process. This causes the oxygen sensor’s performance to eventually dwindle. Its fast capacity to act in response to the alterations in the air and fuel mixture decelerates. In addition to this, the output voltage of your BMW oxygen sensor may plummet in due course. This will result to flawed assessment of the condition of the air and fuel mixture.

At the same time, the sensor’s output voltage may not be as high as it once was, giving the false impression that the air/fuel mixture is leaner than it actually is. The result can be a richer-than-normal air/fuel mixture under various operating conditions that causes fuel consumption and emissions to rise.

When Must You Replace BMW Oxygen Sensor?

Since your oxygen sensor’s quality is reduced as it is constantly used, it is important to replace it. The question is…WHEN? When is the time to change old oxygen sensor? How do you know that your BMW oxygen sensor needs to be replaced? Here are two options:

Check out the light that indicates oxygen sensor change. This is rather easy for vehicle owners whose automobiles have a defective-o2sensor-warning light. But unfortunately, most cars are not equipped with such kind of indicator. So if this is your case, just try Option # 2.

Observe the output voltage of your BMW oxygen sensor. If your output voltage matches up with the condition of your air and fuel mixture, then your oxygen sensor is still functioning well.

Remember: High output voltage = rich mixture Low output voltage = lean mixture

Once you discover that your BMW oxygen sensor is not working properly, replace it immediately. Do not wait for it to totally break down. Oxygen sensor replacement as maintenance should be done within appropriate mileage intervals:

  • Unheated oxygen sensors on 1976 to early 1990s vehicles

Recommended Mileage Replacement Interval: Every 30,000 – 50,000 miles

  • Heated (1st generation) oxygen sensors on mid-1980s to mid-1990s vehicles

Recommended Mileage Replacement Interval: Every 60,000 miles

  • Heated (2nd generation) oxygen sensors on mid-1990s and newer vehicles

Recommended Mileage Replacement Interval: Every 100,000 miles

Source: Autohaus Arizona


3 Responses to When is it Time to Replace your BMW Oxygen Sensor ?

  1. BMW says:

    Mine went out at 60K miles.

  2. Shahadak says:

    What is the difference between Oxygen Sensor and Lamda Sensor ? Are they the same ? When the light indicator is lighted on the dashboard panel, should I change 1, 2 or all 4 ? These are costly items.

  3. autofrankie says:

    Hey Shahadak, a Lambda sensor is essentially the same as an oxygen sensor. And yes, they are costly items. When the light indicator goes on, I suggest you do some inspecting first to try to check the output voltage of each sensor, then determine if any or all would require instant replacing.

    Now I know that buying more than one oxygen sensor can cause a dent on anyone’s bank account, that’s why you need to determine the extent of the damage first before doing any costly replacements. Hope that helps man. :)

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