Oxygen Sensor Precautions
O2 sensor is equipped with a permanent pigtail which must be protected when the sensor is removed. Ensure sensor is free of contaminants and avoid using cleaning solvents of any type. Sensor may be difficult to remove when engine temperature is less than 120°F (48°C). Always use anti-seize compound on threads prior to installation.
NOTE:
Fuel pressure must first be released before performing work on fuel injection components.