Mechanical Gas Fuel System G5.9, G8.3 – 019-100   Heated Oxygen Sensor

WARNING  The oxygen sensor is heated during normal engine operation. To avoid a possible burn injury, before working on the oxygen sensor allow the sensor to cool down following engine shut off.

Wait until the sensor is cool before working on the oxygen sensor.

The sensor will be hot after the engine has been running.

Disconnect the connector from the engine harness.

Remove the sensor.

CAUTION  Only use anti-seize compounds approved by Cummins Inc. for use with heated oxygen sensors. Other anti-seize compounds can damage the sensor.

CAUTION  Do not grease the connectors. The sensor will not function correctly with grease in the connectors.

Apply an approved anti-seize compound to the new sensor threads.

Install the heated oxygen sensor.

WARNING  Natural gas is explosive and flammable. Keep all cigarettes, flames, pilot lights, arcing equipment, and switches out of the work area and areas sharing ventilation to reduce the possibility of severe personal injury or death when working on a natural gas fuel system.

NOTE: The lean burn oxygen sensor
must be calibrated each time it is replaced.

Remove the access plug located between the turbocharger and muffler.

Install a temporary steel line at the connection and route to a side of the engine to allow the connection of an exhaust oxygen meter.

Do
not leave the exhaust oxygen meter connected to the exhaust for extended periods, as moisture will accumulate and enter the meter and cause erroneous readings.

Start the engine.

Once at operating temperature, take the engine to rated rpm and full load.

Using an exhaust oxygen meter, compare the reading from the meter with the exhaust oxygen specification.

Excess O
₂ Percent: 8.6 percent

If the values do
not match, adjust the lambda offset value on the Cummins Air Fuel Ratio (AFR) display.

From the home screen of the Cummins Air Fuel Ratio display, press the “Tweak” button.

Enter the user-defined password.

Select the “AFRADJ” button (A).

Select the “RICHER” button (B) to decrease the exhaust oxygen reading.

Select the “LEANER” button (C) to increase the exhaust oxygen reading.

Allow adequate time between adjustments for the oxygen meter to react to the new condition. This can take up to 30 seconds.

Continue to adjust until the exhaust oxygen meter reading matches the target exhaust oxygen value.
Refer to Procedure 018-016 (Fuel System Specifications) in Section V.

Select the “Exit” button (D) when the desired percent oxygen value is reached to save the new offset.

Remove the exhaust oxygen meter.

Apply a high-temperature anti-seize compound to the threads of the access plug.

Install and tighten the plug.