SPRING 3S4818 - Caterpillar

Probable Causes
Excessive inlet manifold air pressure
The Low Heat Value (LHV) of the gas or the specific gravity of the gas is significantly different from the value that is programmed.
The oxygen sensor is not accurate.Recommended Repairs
Check the Inlet Manifold Air Pressure
The calculated engine load increases when the inlet manifold air pressure increases. Measure the inlet manifold air pressure during engine operation with a load. For specific data on the engine, refer to the engine Technical Marketing Information.Obtain a Fuel Analysis and Program the Fuel Energy Content
Obtain an analysis of the gas in order to determine the LHV. Program the correct LHV for the "Fuel Quality" configuration parameter.If the LHV of the gas does not match the "Fuel Quality" parameter value that is programmed into the ECM, program the master ECM with the correct value for the "Fuel Quality" parameter by selecting the "Change" button in the lower left corner of the screen. Type the correct value and then select "OK".If the quality of the gas is not consistent, obtain several analyses over a period of time. Program the "Fuel Quality" configuration parameter to the average value of the LHV.Check the Oxygen Sensor
Calibrate the oxygen sensor. Refer to Troubleshooting, "Oxygen Sensor - Calibrate".If the oxygen sensor could not be calibrated successfully, refer to Troubleshooting, "Oxygen Sensor Buffer Supply" and Troubleshooting, "Oxygen Sensor Signal".