The BMW Diagnostic Trouble Code (DTC) P1191 corresponds to a "Fuel Control (Bank 2 Sensor 2)" condition. Here's what it typically means:
**P1191 - Fuel Control (Bank 2 Sensor 2)**
This DTC indicates that there is an issue with fuel control in Bank 2, specifically related to the oxygen sensor 2 (Sensor 2). Bank 2 typically refers to the side of the engine where cylinders 4 through 6 are located, and Sensor 2 is the downstream oxygen sensor in that bank. The engine control module (ECM) has detected a problem with the fuel control system downstream of the catalytic converter, often related to an incorrect air-fuel mixture.
Common causes of a P1191 code in a BMW include:
1. **Faulty Oxygen Sensor:** The oxygen sensor (Sensor 2) in Bank 2 may be malfunctioning or providing incorrect data to the ECM.
2. **Exhaust Leaks:** Leaks in the exhaust system downstream of the oxygen sensor can affect sensor readings and lead to incorrect fuel control.
3. **Catalytic Converter Issues:** Problems with the catalytic converter, such as damage or deterioration, can affect sensor readings and fuel control.
4. **Wiring or Connector Problems:** Damaged or corroded wiring, connectors, or terminals related to the oxygen sensor can result in communication errors.
To diagnose and address a P1191 code, a qualified technician typically performs the following steps:
1. **Visual Inspection:** Inspect the exhaust system for leaks downstream of the oxygen sensor and check the wiring, connectors, and terminals related to the oxygen sensor for damage or corrosion.
2. **Inspect Oxygen Sensor:** Test the operation of the oxygen sensor (Sensor 2) to ensure it is functioning correctly.
3. **Catalytic Converter Inspection:** Check the condition of the catalytic converter to ensure it is functioning properly.
4. **Data Monitoring:** Use a diagnostic scan tool to monitor live data, including oxygen sensor readings, to help identify the source of the issue.
