Why study the clutter signals on the waveform of oxygen sensors?
This is because the clutter may be caused by low combustion efficiency. As long as the upflow system is not in the correct working state, the catalyst cannot be accurately tested. The clutter of the oxygen sensor waveform can warn of a decrease in the performance of each engine cylinder. At this time, exhaust gas diagnosis is the most important. Because it can detect a decrease in the conversion efficiency of the catalyst and a decrease in the performance of individual cylinders. Clutter signals also hinder the normal operation of the fuel feedback control system controller (in the feedback program running on the engine control computer). The "fuel feedback control system controller" specifically refers to the software program that works (referred to as the "feedback controller"). It is a program that receives oxygen sensor voltage signals and calculates correct real-time fuel injection or mixture control commands. Usually, feedback controller programs are not designed to effectively handle the frequency of oxygen sensor signals generated by abnormal system operations and fuel control commands. Chaotic high-frequency fluctuation signals can cause the feedback controller to lose control accuracy or "feedback rhythm". There are several impacts here. Firstly, when the operational accuracy of the feedback controller is affected, the fuel mixture ratio will exceed the catalyst window, which will affect the efficiency of the converter and exhaust emissions. Secondly, engine performance will also be affected. Clutter can become a decisive indicator of uncontrolled exhaust gas entering the catalyst. It is often found that when clutter exists, the exhaust gas entering the catalyst does not have the correct air-fuel ratio of the mixture. Understanding the clutter on the waveform of the oxygen sensor is important for repairing and diagnosing exhaust emissions. In some cases, clutter is a clear signal of a decrease in catalytic conversion efficiency, followed by exhaust emissions exceeding standards. In addition, the interpretation of clutter on the waveform of oxygen sensors is a valuable tool for diagnosing engine performance or driving ability. Clutter is an indication of combustion efficiency imbalance from one cylinder to another. The interpretation and understanding of the clutter on the waveform of the oxygen sensor is also important for effectively using the oxygen sensor signal for repair and verification. The clutter on the waveform of the oxygen sensor indicates an imbalance in exhaust changes from one cylinder to another, or rather a lack of high oxygen content in individual combustion processes. Most oxygen sensors can quickly provide feedback on the voltage deviation generated during various combustion processes when working properly. The greater the signal limitation of the clutter, the greater the difference in oxygen composition measured from various combustion processes. The clutter observed under different driving modes is not only important for determining the root cause of steady-state and transient exhaust gas test failures, but also an effective diagnostic basis for drivability. The oxygen sensor signal clutter, which forms a one-to-one exhaust gas waveform with the peak burr of BC under acceleration mode, is a very important diagnostic signal because it means that there is a misfire phenomenon during ignition under load. Usually, the larger the amplitude of the clutter. The more components of the oxygen sensor in the exhaust, the higher the noise is due to the increase in the average oxygen content of the feedback gas entering the catalytic converter, which indicates an increase in nitrogen oxide emissions. In a rich oxygen environment (lean mixture), the nitrogen oxide in the catalytic converter cannot be reduced (chemically). In summary, it is known that some types of feedback systems