What are the causes of the air-fuel ratio malfunction in the Teana?
3 Answers
Teana air-fuel ratio malfunction causes: Fuel emission system malfunction: The air-fuel ratio malfunction is caused by the fuel emission system. When the malfunction indicator light is on, start and turn off the vehicle three times, then start the vehicle again to observe whether the malfunction indicator light remains on. If it remains on, it is necessary to promptly go to the shop to check the fault code to determine whether it is an engine issue or a sensor malfunction. If the light does not come back on, it may be an intermittent fault and does not require immediate shop inspection. Abnormal exhaust emissions: When the computer receives parameters from the oxygen sensor indicating that the exhaust emissions severely exceed the national legal standards, and the computer's internal program cannot adjust them back to the standard range, the engine control computer will then illuminate the pollution emission warning light on the dashboard to alert the owner to check the cause of the engine pollution emission light at a service station.
I've been driving for over a decade. When my Teana had an air-fuel ratio malfunction, it felt like the engine was shivering, and the fuel consumption skyrocketed. When I encountered this issue, it turned out to be a faulty oxygen sensor. This component monitors the air-fuel ratio in the exhaust pipe, and if the data is inaccurate, the computer makes incorrect adjustments. Another culprit was the dirty mass air flow sensor, which miscalculated the air intake and caused an imbalance. Additionally, my air filter hadn't been replaced for months and was clogged with dust, restricting airflow and leaving the engine 'half-starved.' The most troublesome part was the fuel injector—if it leaks or gets clogged with carbon deposits, it can't control the fuel accurately. I recommend not disassembling things blindly; instead, use an OBD scanner to read the fault codes and pinpoint the issue to avoid wasting money on unnecessary parts. Regular maintenance of these components, like cleaning sensors and replacing filters, can help prevent such problems.
As someone who enjoys tinkering with cars, I find that there are quite a few causes for air-fuel ratio malfunctions, with sensor issues being the most common. If the oxygen sensor (O2) ages or fails, it tricks the computer into thinking the air-fuel ratio is off. A dirty mass airflow sensor (MAF) or loose wiring can also mislead the data. That time my car had unstable idling and black smoke from the exhaust was due to a faulty MAF—I took it out, cleaned it with alcohol, and it worked fine again. Sometimes, the engine control unit (ECU) can also have bugs that prevent it from correctly controlling the mixture, or the fuel pump pressure might be unstable, causing the injectors to malfunction. Don’t overlook small issues like vacuum leaks in the intake manifold, which allow extra air into the engine and disrupt the ratio. First, check if the wiring connections are secure and clean the MAF and O2 connectors. If that doesn’t work, then seek professional help for tuning. This approach saves time and money while also helping you gain experience.
