The oxygen (lambda) sensor is responsible for measuring the amount of oxygen in the exhaust gases. This information is used by the engine control unit (ECU) to adjust the air/fuel mixture. If the oxygen sensor is not working properly, it can cause the engine to run rich or lean, which can lead to decreased performance, increased fuel consumption, and emissions.
The P1128 fault code specifically indicates that the oxygen sensor located in Bank 1 (the side of the engine with cylinder 1) and Sensor 2 (the sensor located after the catalytic converter) is not switching between rich and lean states frequently enough. This can be caused by a faulty oxygen sensor, a wiring issue, or a problem with the ECU.
To diagnose the P1128 fault code, you will need to:
* Inspect the oxygen sensor for damage.
* Check the wiring to the oxygen sensor for damage or corrosion.
* Test the oxygen sensor using a scan tool.
* Check the ECU for updates or faults.
If you are not comfortable performing these tasks, you should take your vehicle to a qualified mechanic.
