1. Faulty Oxygen Sensor: The HO2S, also known as the O2 sensor, may be defective or have failed, causing inaccurate readings. This can affect engine performance and fuel efficiency.
2. Wiring Issues: Check for any loose, damaged, or corroded wiring or connectors related to the HO2S Bank 2 Sensor 1. Poor electrical connections can disrupt the communication between the sensor and the Engine Control Unit (ECU).
3. Exhaust System Leaks: Leaks in the exhaust system, especially near the HO2S, can cause inaccurate readings. Exhaust gas leaks can skew the oxygen levels that the sensor detects.
4. Fuel Issues: Rich or lean fuel mixtures can also trigger the DTC 43. Check for fuel injector problems, fuel pressure issues, or vacuum leaks that can impact the air-fuel ratio.
5. ECU Malfunction: In rare cases, the ECU may be experiencing an internal fault that affects the processing of signals from the HO2S.
To diagnose the exact cause, it is recommended to retrieve the freeze frame data from the OBD-II scanner and perform tests to verify the functionality of the HO2S and the related components. If necessary, the faulty oxygen sensor should be replaced, wiring issues fixed, or exhaust leaks repaired.
