The Usual Signs of a Malfunctioning Audi A4 Oxygen Sensor
Your Audi A4's oxygen sensor is an essential part of the car because it determines the correct fuel-to-air ratio for the engine. However, it only has a limited service life particularly for older models, and it could lead to different problems once it malfunctions. When you start to notice that your vehicle is acting unusual, you should do some troubleshooting immediately to determine if the problem is coming from a faulty oxygen sensor. Enumerated below are some of the common problems you can encounter:
Poor fuel mileage
When the oxygen sensor of your car begins to malfunction, your car will start to experience a decrease in fuel mileage. This happens when a faulty sensor determines the wrong amount of fuel-air mixture, and the amount of fuel that's sent to the engine's cylinders increases. Although there are other causes of poor gas mileage, you should include the oxygen sensor in the list of parts to check. When the oxygen sensor gets fixed, the fuel consumption of your vehicle can improve by as much as 40 percent.
Rough idling and stalling
Since the oxygen sensor in your car contributes to various engine functions like engine timing and engine combustion intervals, a defective oxygen sensor can be the cause of rough engine idling. The sensor in your car can become clogged because of contaminants like lead or carbon that comes from the engine. Air leaking in the exhaust manifold can also affect the performance of the sensor. You can try to clean or repair the sensor and the exhaust manifold when this happens, but replacing these parts is the best solution.
Increased vehicle emission
Another common problem you will notice when your Audi A4 oxygen sensor begins to malfunction is the increase in smoke emission. A bad oxygen sensor won't be able to measure the correct fuel-to-air ratio, and it will only cause unnecessary amounts of fuel to be sent to the engine. The unburned fuel will later accumulate and become toxic gases. A good preventive maintenance for an oxygen sensor is replacing it every 100,000 miles. This will help your vehicle meet the emissions test requirements.