Detroit Diesel NOx Sensors
Detroit Diesel NOx sensors monitor nitrogen oxide levels in diesel exhaust systems and play a critical role in SCR (Selective Catalytic Reduction) emissions control. These sensors provide real-time exhaust data to the engine control module, allowing the system to regulate DEF dosing and maintain emissions compliance. At Advanced Truck Parts, we supply Detroit Diesel NOx sensors designed for reliable operation in heavy-duty diesel trucks.
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Detroit Diesel NOx Sensors in SCR Aftertreatment Systems
SCR-equipped Detroit Diesel engines rely on NOx sensors to measure nitrogen oxide levels in the exhaust stream. This information allows the ECM to control Diesel Exhaust Fluid (DEF) injection and ensure proper reduction of NOx emissions.
Most Detroit Diesel aftertreatment systems use two sensors:
- Upstream NOx sensor located before the SCR catalyst
- Downstream NOx sensor located after the SCR catalyst
Together, these sensors help maintain proper SCR efficiency and verify that the emissions system is functioning correctly.
Common Detroit Diesel Engine Applications
Detroit Diesel NOx sensors are widely used across heavy-duty diesel engines found in Freightliner trucks and commercial fleet vehicles.
- Detroit Diesel DD13 engines
- Detroit Diesel DD15 engines
- Detroit Diesel DD16 engines
- Freightliner Cascadia and other Freightliner platforms
Because emissions configurations and wiring connectors vary by model year, matching the correct sensor part number is important when replacing a NOx sensor.
Common NOx Sensor Failure Symptoms
- SCR or emissions system warning lights
- NOx sensor diagnostic fault codes
- Incorrect DEF dosing
- Engine derate or limited power mode
- Aftertreatment efficiency faults
NOx sensors may fail due to extreme heat exposure, contamination from exhaust deposits, wiring damage, or internal electronic failure. Replacing a faulty sensor helps restore accurate emissions monitoring and prevent aftertreatment system faults.
Upstream vs Downstream NOx Sensors
Detroit Diesel engines typically use two NOx sensors that perform different monitoring functions:
- Upstream sensor: measures engine-out NOx levels so the ECM can determine proper DEF injection.
- Downstream sensor: confirms that the SCR catalyst is reducing NOx emissions effectively.
If either sensor fails, the engine control system may trigger emissions fault codes and activate engine derate protection.
Verify Fitment Before You Buy
NOx sensors vary depending on engine model, emissions configuration, and truck production year. To confirm compatibility before ordering, provide:
- Engine serial number
- Truck year / make / model
- Current NOx sensor part number
- Photos of the sensor or wiring connector if available
This information helps ensure the correct Detroit Diesel NOx sensor is selected for your truck.
Why Buy Detroit Diesel NOx Sensors from Advanced Truck Parts?
- Fitment verification before purchase
- Reliable emissions system components
- Fast shipping to minimize truck downtime
- Support for fleets, repair shops, and owner-operators
- Competitive pricing on diesel aftertreatment parts
