Detroit Diesel Outlet NOx Sensor | PN A101538128

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The Detroit Diesel Outlet NOx Sensor (A101538128) monitors nitrogen oxide levels in the exhaust stream downstream of the SCR catalyst in Freightliner Cascadia DD15 trucks. This sensor verifies that the SCR system is achieving the required NOx reduction to meet EPA emissions standards. A faulty outlet NOx sensor triggers fault codes, forces the engine into derate mode, and causes failed emissions inspections. Timely replacement with this genuine Detroit Diesel sensor restores full SCR operation.

Q: Which trucks does this NOx sensor fit?
A: Fits Freightliner Cascadia trucks with Detroit Diesel DD13 and DD15 engines. Genuine part A101538128.

Q: What fault codes does a failing outlet NOx sensor trigger?
A: Common codes include SPN 3226 and SCR outlet NOx efficiency faults in Detroit Diesel DiagnosticLink (DDL).

Q: What is the difference between inlet and outlet NOx sensors?
A: The inlet sensor measures NOx before the SCR catalyst; the outlet sensor measures NOx after to verify SCR efficiency. Both must function for emissions compliance.

Q: Is this a genuine Detroit Diesel part?
A: Yes. This is a genuine OEM Detroit Diesel NOx sensor — using genuine parts ensures proper calibration with the DD15 aftertreatment system.

Q: Will a faulty NOx sensor cause engine derate?
A: Yes. A failed outlet NOx sensor triggers progressive derate after a set number of hours to enforce emissions compliance.