VALVE GP-PRIORITY 7T8557 - Caterpillar

oxygen sensor is very important for these considerations:
Control of emissions
Engine performance
During operation, the oxygen sensor may reach temperatures that exceed 700 °C (1292 °F). Severe personal injury and property damage will result from contact with a hot oxygen sensor.Do not touch the sensor during engine operation, calibration, or testing. Allow the sensor to cool before moving the sensor. Wear gloves that resist heat. Do not place the sensor on or near any flammable material or any surface that can be damaged by high temperatures.
The sensor must be calibrated periodically in order to ensure proper operation. If a new sensor will be installed, calibrate the new sensor before installation.During calibration, the sensor must be temporarily removed from the exhaust system. It is necessary to expose the sensor to clean air.Note: When you reinstall an oxygen sensor, always use a new 9Y-6792 Spark Plug Gasket.DO NOT calibrate the sensor in an environment with the following conditions:
The ambient temperature is greater than 38 °C (100 °F).
The relative humidity is greater than 90 percent.For instructions, refer to Service Manual, RENR2270, "Troubleshooting".