LENS 3A1144 - Caterpillar

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Secure O2 sensor wiring using the required parts listed in Table 2.Install the O2 sensors within 30.5 cm (12 inch) from the catalyst. The O2 sensors should be installed at the top half of the exhaust pipe on either side of the catalyst in a horizontal application. In a vertical mounted catalyst, install the O2 sensors perpendicular to the pipe. Refer to Illustration 4 and 5.Note: If installing on a non-close coupled catalyst configuration, the catalyst inlet Wide Band O2 sensor will need to be installed within 30.5 cm (12 inch) from the catalyst and at least 6.4 cm (2.5 inch) into the exhaust stream of the catalyst inlet.Note: Do NOT insulate the O2 sensors.
Proper Strain Relief
The harness should be secured every 6 inches or less over the entire length of the harness.
Any harness bend radius should not exceed 20 mm.
The harness that exits the O2 sensor probe should not exceed a 15 degree angle to allow for proper strain relief at the sensing probe assembly.
Overall bend distance at the probe should be a minimum of 60 mm.
Since stoichiometric varies with fuel property, the AFR control needs set up to deliver the optimum AFR for the fuel quality at the site. Setting up the AFR control involves adjustment of the input "Desired Emissions Gain Adjustment Percentage" as needed to meet emissions with the fuel quality on site. This input can be adjusted using Cat ET. Follow the procedure described in the next section to set this input. The parameter needs set upon first commissioning and thereafter verified & adjusted upon changes in fuel quality. Check the parameter every 750 hours for the initial 3000 service hours and every 1500 hours afterwards to ensure that emissions are met over time.Desired Emissions Gain Adjustment Percentage Adjustment
With the ECM powered up and the engine not running, check for diagnostic codes or events. If no diagnostic codes or events are present, proceed with adjustment of "Desired Emissions Gain Adjustment Percentage" parameter.
Start the engine.
Monitor the coolant and oil temperatures and when appropriate, apply load as needed to reach maximum operating load. Ensure that the load is maintained as steady as possible. Verify that the catalyst temperatures have stabilized.
Connect service tool to the ECM, check if the AFR control is operating in closed loop by following the procedure below.
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At the menu bar, go to the "Diagnostics" menu and select "Diagnostic Tests".
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Double-click "System Troubleshooting Settings".
Double-click "Emissions Feedback Mode". The current value should read "Oxygen Feedback".Note: Once the service tool is disconnected, the AFR control will default to closed loop control once the appropriate conditions are met.
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Measure and record the emissions downstream of the catalyst. Record the initial value of the input "Desired Emissions Gain Adjustment Percentage", if the emissions data was recorded with the input set to 0 percent, record 0 percent.Note: Adjust the parameter, in the section below, to meet the emissions. At each adjustment setting, wait at least 10 minutes between each adjustment. The 10 minutes will allow