BMW X5 Oxygen Sensor 11787539125 Replaces 0258006793 0258006864

When BMW X5 exhibits rough idle, high fuel consumption, or frequent check engine lights, this is typically due to oxygen sensor aging or failure. The sensor monitors exhaust oxygen content and feeds back to the ECU to precisely control air-fuel ratio for efficient engine operation and compliant emissions. OEM number: 11787539125; replacements include 0258006793 and 0258006864; fits X5 (E70/E71) and some N55-engine-equipped models. Installation must be performed cold; use a dedicated sleeve to avoid thread or wiring interface damage.