Innovate Motorsports 3729 Heat-Sink Bung Extender HBX-1
The Bosch LSU4.2 wide-band O2 sensor is rated to operate at an exhaust gas temperature of < 1300 degrees (F), and a sensor housing temperature of < 900 degrees (measured at the bung) for maximum accuracy and control. When either of these operating temperature ranges is exceeded, the sensor can no longer be accurately controlled. Further, operating at or over these temperatures for any length of time can significantly reduce the lifetime of the sensor. The HBX-1 is intended to provide a degree of thermalisolation in applications where the pipe temperature exceeds 900F (approx. 500c) with a heat-sinking design intended to screw into a new or existing 18mm bung.