Buick New Regal Oxygen Sensor 12617648, 149100-7040 Preferred for Improved Combustion Efficiency

When your Buick Regal exhibits check engine light, noticeably higher fuel consumption, weak acceleration or sour exhaust odor, likely oxygen sensor aging causing air–fuel imbalance. This sensor monitors exhaust oxygen content and feeds ECU to control injection, ensuring combustion efficiency and lower emissions. OEM numbers 12617648 (OEM) and 149100-7040; fits all Buick Regal models. Install with a dedicated socket; avoid overtightening and clean exhaust interface; ensure sensor harness does not contact high-temperature parts.