HBX-1 Heat-Sink Bung Extender Use With IM3737 Oxygen Sensor

The Bosch LSU4.2 wide-band O2 sensor (shipped as part of the LM-1 kit) is rated to operate at an exhaust gas temperature of 1300°F, and a sensor housing temperature of 900°F (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 LM-1 is designed to display an error message under these conditions (currently 08- Sensor Timing Error) rather than provide inaccurate readings. For some turbo vehicles, rotary engines, and other setups, this error message can be encountered with annoying frequency.