BMW Oxygen Sensor 11787589121 High-precision sensor, compatible with 0258027029/234-5054

When a BMW experiences rough idle, abnormal fuel consumption, or engine fault light, it is likely the oxygen sensor aging and failing; the sensor normally feeds ECU with lean-burn data to maintain emissions and efficiency. OEM number 11787589121; compatible with 0258027029/234-5054; fits 3-Series, 5-Series, X3 and other models with N20/N55 engines. Installation requires cold engine operation; avoid sensor cable contact with exhaust hot areas; after installation, use a diagnostic tool to clear fault codes and reset learning.