High-Quality OEM Replacement Inlet NOx Sensor

This inlet NOx sensor is compatible with the following Detroit Diesel engine applications:

• DD13 – Inlet position, 2010 to 2016
• DD15 – Inlet position, 2010 to 2016
• DD16 – Inlet position, 2010 to 2016

This is the inlet (upstream) sensor — positioned before the SCR (Selective Catalytic Reduction) system. To confirm 100% compatibility, please match the OE Part Numbers listed in our specifications with those on your original unit, or contact us with your vehicle's VIN before purchasing.

A NOx (Nitrogen Oxide) sensor measures the concentration of nitrogen oxide gases in the exhaust stream. The inlet sensor is positioned upstream of the SCR (Selective Catalytic Reduction) system and performs a critical role in the emissions management process:

• Emissions Monitoring: Measures raw NOx output from the engine before it enters the SCR system
• DEF Dosing Control: Provides data to the ECM to calculate the correct amount of Diesel Exhaust Fluid (DEF/AdBlue) to inject into the SCR catalyst
• Engine Management: Feeds real-time data to the engine control module to optimise combustion and reduce NOx output
• Regulatory Compliance: Ensures the vehicle meets EPA emissions standards and avoids fault codes, derate conditions, and failed inspections

A failed inlet NOx sensor can trigger fault codes, cause engine derate, increase DEF consumption, and lead to failed emissions testing.

Detroit Diesel DD-series engines use two NOx sensors working together as part of the SCR emissions system:

• Inlet NOx Sensor (This Product): Positioned before the SCR catalyst — measures the raw NOx concentration entering the emissions system from the engine. This data is used to calculate the correct DEF injection rate.
• Outlet NOx Sensor: Positioned after the SCR catalyst — measures the treated NOx leaving the system to verify the SCR catalyst is converting NOx effectively and that DEF dosing is accurate.

Both sensors must function correctly for the SCR system to operate accurately. A fault in either sensor will typically trigger a fault code and may cause engine derate. This listing is for the inlet sensor only — please ensure you order the correct position for your application.

Common signs of a failing or failed inlet NOx sensor on a DD13, DD15, or DD16 engine include:

• Illuminated Check Engine Light (MIL) or emissions warning light
• Active fault codes related to NOx sensor circuit or signal — commonly SPN 3216, SPN 3226, or SPN 3227
• Engine derate — reduced power output or speed limitations imposed by the ECM as a protective measure
• Excessive DEF (AdBlue) consumption due to incorrect dosing calculations
• Failed emissions inspection or roadside compliance check
• Poor fuel economy caused by suboptimal combustion management
• SCR system fault warnings or SCR efficiency codes

If any of these symptoms are present, have the sensor tested and fault codes diagnosed by a qualified technician before replacing components.

Self-installation is not recommended. Professional installation by a qualified technician is strongly recommended for the following reasons:

• Diagnostic Equipment Required: After fitting a new NOx sensor, the ECM must have existing fault codes cleared using specialist diagnostic software — simply replacing the sensor without clearing codes may not resolve the fault
• Sensor Calibration: Some installations require the sensor to be recognised and calibrated by the engine management system
• Correct Torque Application: NOx sensors fitted in exhaust positions must be torqued correctly to prevent exhaust leaks and sensor damage
• Warranty Activation: Professional installation is required to activate the 10-Year Extended Warranty

Note: Installation instructions are not included with this product.

Replacing a faulty inlet NOx sensor will resolve the underlying cause of sensor-related fault codes — however, the fault codes and derate condition will not clear automatically simply by fitting the new sensor. A qualified technician must:

• Connect specialist Detroit Diesel diagnostic software (such as DiagnosticLink) to the ECM
• Clear the stored fault codes after the new sensor is fitted
• Verify the new sensor is reading correctly within the expected parameters
• Confirm the derate condition has been lifted by the ECM

If fault codes persist after sensor replacement and code clearing, additional diagnosis may be required to rule out wiring harness faults, connector corrosion, or ECM issues.

This inlet NOx sensor uses the following connector specification:

• Connector Type: 4-Pin Connector
• Connection Gender: Female (the sensor body has a female connector that accepts the male vehicle harness plug)
• Terminal Gender: Male — Blade & Bullet Type terminals inside the connector
• Voltage: 12V operating voltage

This connector configuration is a direct match for the factory wiring harness on Detroit Diesel DD13, DD15, and DD16 engines from 2010 to 2016. No wiring modifications or adapter harnesses are required — the sensor is a true plug-and-play replacement.

We offer two warranty levels:

• 10-Year Extended Warranty: Activated when the product is installed by a fully qualified professional. You must submit a copy of your garage fitment invoice within 30 days of installation to activate this coverage.
• 1-Year Standard Warranty: Applies by default if no garage invoice is submitted within 30 days of purchase.

All warranty coverage applies to the product only and excludes labour costs, diagnostic charges, installation fees, or any additional expenses incurred.

This is a high-quality aftermarket replacement part engineered to meet or exceed OEM (Original Equipment Manufacturer) specifications. It is 100% brand new and designed as a direct replacement for the factory inlet NOx sensor on Detroit Diesel DD13, DD15, and DD16 engines.

It delivers the same fit, connector compatibility, signal accuracy, and emissions management function as the original factory sensor — at a more competitive price point than a Detroit Diesel genuine part, without compromising on precision or reliability.

To confirm 100% compatibility before purchasing, follow these steps:

• Confirm Engine Model: Verify your engine is a Detroit Diesel DD13, DD15, or DD16
• Check Year Range: Confirm your engine is from the 2010 to 2016 production range
• Confirm Sensor Position: Ensure you require the inlet (upstream) sensor — positioned before the SCR catalyst. This is NOT the outlet sensor.
• Match OE Part Numbers: Compare the OE Part Numbers in our specifications (A0101531928, 0101531928, A2C89603500, A2C89603500-01, 5WK97341A) against the number on your original sensor body or engine documentation
• Contact Us with Your VIN: Provide your vehicle or engine VIN and our team will confirm exact fitment before you order

The compatibility chart is for general reference only. Matching the OE part number on your original unit — or consulting your main dealer — is the most reliable method to confirm correct fitment.

NOx sensor lifespan on Detroit Diesel DD-series engines varies depending on operating conditions, DEF quality, and maintenance practices. Under normal operating conditions, NOx sensors can last between 200,000 and 400,000 miles — however, several factors can cause premature failure:

• DEF Contamination: Using low-quality or contaminated Diesel Exhaust Fluid can damage sensor elements over time
• Thermal Stress: Repeated heat cycling in high-demand commercial applications can degrade sensor components
• Connector Corrosion: Moisture ingress into the wiring harness connector can cause signal faults before the sensor itself fails
• Extended Idling: Prolonged low-temperature operation prevents the exhaust system from reaching optimal operating temperature, accelerating sensor fouling
• Oil or Coolant Contamination: Engine oil or coolant entering the exhaust stream can coat and damage the NOx sensing element

Regular emissions system maintenance and use of high-quality DEF fluid are the most effective ways to maximise NOx sensor service life on DD-series engines.