Some drivers may not pay much attention to the fuel consumption of their vehicles, while others do. Usually, they will fix the amount of refueling, such as 200 yuan each time, and reset the mileage after refueling. When you refuel next time, you can see if the fuel consumption has changed by observing the change in the number of kilometers traveled. For example, 200 yuan can travel 400 kilometers, but now it can only run 300 kilometers, which suggests that the fuel consumption may have increased. Changes in fuel consumption are often related to some potential faults of the vehicle. Therefore, understanding the changes in fuel consumption can help us detect and solve vehicle problems in a timely manner.
There are many reasons for increased fuel consumption. Today we will discuss a component that is not well known to people - the oxygen sensor. Under normal circumstances, the oxygen sensor does not affect fuel consumption. It will only affect fuel consumption when it fails or the value is inaccurate. The oxygen sensor is installed on the exhaust pipe to detect the oxygen content in the exhaust gas, so as to judge the combustion state and adjust the injection amount accordingly. For example, when the oxygen sensor detects that the oxygen content in the exhaust gas is too high, it means that the ratio of air to gasoline is unbalanced, and the gasoline is burned out but there is still oxygen left, that is, too little fuel is injected and the mixture is too lean. At this time, the oxygen sensor will send a signal to the engine computer to increase the amount of fuel injection to achieve the best air-to-gasoline ratio. Conversely, when the oxygen content is too low, it means that the mixture is too rich, and the amount of fuel injection needs to be reduced. Therefore, the normal operation of the oxygen sensor has a positive impact on the combustion state, emissions and fuel consumption.
The normal working temperature of the oxygen sensor is about 300 degrees, so when the vehicle is just started, the oxygen sensor cannot enter the working state immediately. In order to speed up the speed at which the oxygen sensor reaches the normal working temperature, modern vehicles are usually equipped with heated oxygen sensors, which can automatically heat up in the cold state and quickly reach the appropriate working temperature. The engine open-loop control and closed-loop control that you may have heard of actually describe whether the oxygen sensor is involved in the work. When the oxygen sensor is involved in the work, we call it closed-loop control; otherwise, it is open-loop control. Closed-loop control can ensure that the ratio of air to gasoline is maintained near the theoretical value, so that the gasoline can be completely burned. Therefore, oxygen sensors play a very important role in fuel correction.
If there is an error in the signal transmission of the oxygen sensor and it continues to send a signal that the oxygen content is too high to the engine computer, the engine computer will increase the amount of fuel injection, resulting in an overly rich mixture, which in turn increases fuel consumption. In most cases, when the oxygen sensor fails, the vehicle's engine fault light will light up, prompting the driver to repair it in time. But sometimes, the oxygen sensor may just be working insensitively and not completely damaged, so no fault code will be generated, and the engine fault light will not light up, which may cause the driver to fail to detect the abnormal increase in fuel consumption. To determine whether there is a problem with the oxygen sensor, it is usually necessary to check the data stream. Under normal circumstances, the data of the oxygen sensor should be constantly changing. If there is no change for a long time, it means that there may be a fault.
One of the main reasons for oxygen sensor damage is poisoning, which is similar to the reason for the damage of the three-way catalytic converter, often due to the use of poor quality gasoline. If the lead content in gasoline exceeds the standard, long-term use may cause oxygen sensor damage. Therefore, vehicles that often refuel at small private gas stations have a relatively high risk of oxygen sensor damage. Although the vehicle can still be driven after the oxygen sensor is damaged, it will not be able to accurately correct the fuel injection amount, resulting in the air-fuel ratio not being able to reach the optimal state, which may cause problems such as increased fuel consumption, incomplete combustion, and substandard emissions. Therefore, once the oxygen sensor is found to be damaged, it should be replaced in time because it cannot be cleaned or repaired.