High-Quality OEM Replacement NOx Sensor Assembly

This NOx sensor assembly is specifically engineered for the following platforms:

• Freightliner Cascadia (2012–2022) — equipped with Detroit Diesel DD13 or DD15 engines
• Western Star 5700XE (2016–2022) — equipped with Detroit Diesel DD13 or DD15 engines
• Detroit Diesel DD13, DD15, and DD16 engine compatibility

To confirm 100% exact fitment, please match the OE Part Numbers in our specifications against those on your original NOx sensor, or contact us with your vehicle's VIN or truck registration number before purchasing.

A NOx (Nitrogen Oxide) sensor is a precision emissions monitoring device that measures nitrogen oxide levels in the exhaust stream. On Freightliner Cascadia and Western Star 5700XE trucks equipped with Detroit Diesel DD13, DD15, and DD16 engines, the NOx sensor performs several critical functions:

• Emissions Monitoring: Continuously measures nitrogen oxide concentration to ensure compliance with EPA and CARB emissions standards
• SCR System Control: Provides data to the engine control module to optimize DEF (Diesel Exhaust Fluid) injection for maximum NOx reduction efficiency
• Engine Performance: Relays real-time emissions data to enable the truck to maintain optimal power delivery while meeting emissions requirements
• Fuel Efficiency: Helps the engine management system maintain efficient combustion and fuel economy under all operating conditions
• Diagnostic Capability: Enables fleet diagnostics and alerts operators to emissions system faults before they become roadside issues

A properly functioning NOx sensor is essential for fleet safety, regulatory compliance, and avoiding costly downtime on long-haul operations.

Common symptoms of a worn or failing NOx sensor on Freightliner Cascadia and Western Star 5700XE trucks include:

• Check engine light or emissions warning light on the dashboard
• Diagnostic trouble codes related to NOx sensors (P240x series codes) stored in engine memory
• Reduced engine power or limp-mode activation — limiting truck speed or power delivery
• Excessive DEF consumption requiring more frequent refilling than normal
• Rough idle or hesitation during acceleration, especially when loaded
• Failed emissions testing or emissions compliance warnings in fleet management systems
• Loss of fuel economy compared to baseline fleet performance
• Engine derating — forced reduction of horsepower and torque due to emissions faults

If any of these symptoms appear, have your truck scanned with heavy-duty diagnostic equipment immediately to prevent extended roadside breakdowns or missed deliveries.

This NOx sensor assembly includes an integrated control unit — meaning the sensor and its associated electronic controller are combined into a single unit. On Freightliner Cascadia and Western Star 5700XE trucks, this integrated design provides several advantages:

• Simplified Installation: The sensor and controller come together as one assembly, reducing installation complexity and connector points
• Direct Replacement: Can be installed as a direct replacement for the OEM unit without requiring separate controller programming or configuration
• Optimized Signal Processing: The integrated controller processes sensor signals immediately and communicates directly with the engine management system
• Diagnostic Accuracy: Integrated electronics provide accurate fault detection and reporting to the truck's onboard diagnostics system
• Factory Calibration: Pre-calibrated for exact compatibility with Freightliner and Western Star emissions system parameters

This integrated design simplifies service and reduces potential points of failure compared to separately mounted sensor and controller configurations.

This listing includes:

• 1x NOx Sensor Assembly with Integrated Control Unit — ready for installation on Freightliner Cascadia or Western Star 5700XE trucks

The complete assembly includes the sensor element, integrated control circuitry, 4-Pin connector, mounting hardware, and factory calibration. Installation instructions are not included but are available separately or from your qualified technician.

Professional installation by a qualified heavy-duty mechanic or Freightliner/Western Star technician is strongly recommended. NOx sensor replacement requires:

• Proper disconnection of the engine management system harness and sensors
• Correct threading and seating of the M20 x 1.5 mounting on the truck's exhaust manifold
• Careful handling to prevent damage to the precision sensing element
• Proper connector installation with the 4-Pin female connector
• Engine diagnostic scanning to clear fault codes and verify sensor integration
• DEF system recalibration and NOx sensor offset adjustment on some model years
• Professional installation is required to validate warranty coverage and maintain fleet emissions compliance

Incorrect installation can result in check engine lights, false emissions warnings, reduced power, or excessive DEF consumption. Note: Installation instructions are not included with this product.

Yes — professional diagnostic service is essential after NOx sensor installation. Your technician should:

• Clear Fault Codes: Use heavy-duty diagnostic equipment to clear all stored emissions fault codes from the engine control module
• System Verification: Monitor live NOx sensor readings to confirm the new sensor is communicating correctly with the truck's engine management system
• SCR Validation: Verify that the SCR system is responding appropriately to sensor data and DEF injection is functioning at normal rates
• Emissions Test: Run emissions diagnostics to ensure the truck is operating within EPA and CARB compliance limits
• Fleet Management Update: If applicable, update fleet management systems to recognize the new sensor and verify emissions data is transmitting correctly
• Test Drive: Complete a test drive under various operating conditions to confirm no new faults develop

Professional diagnostic work ensures the NOx sensor is properly integrated and protects your warranty coverage.

This NOx sensor assembly is compatible with Detroit Diesel DD13, DD15, and DD16 engines as follows:

• DD13 Engine: Standard medium-duty diesel engine used in many Freightliner Cascadia and Western Star 5700XE models from 2012 onwards
• DD15 Engine: Heavy-duty diesel powerplant with increased displacement and power output compared to DD13 — common in modern Cascadia and 5700XE specifications
• DD16 Engine: The newest generation Detroit Diesel engine featuring advanced emissions control and increased efficiency — compatible with this NOx sensor assembly

This sensor has been engineered to work across all three engine variants found in 2012–2022 Freightliner Cascadia and 2016–2022 Western Star 5700XE trucks, ensuring fleet-wide compatibility regardless of specific engine choice. Always verify your truck's specific engine designation before ordering.

This NOx sensor features a 4-Pin rectangular connector with female terminals and sockets. The connector provides:

• Plug-and-Play Simplicity: Rectangular design allows for immediate connection to the truck's factory wiring harness without modification
• Female Configuration: Female connector and terminals mate directly with male pins on the truck's engine harness
• Four-Wire System: The four pins carry: power, ground, signal line, and shield/drain wire
• Factory Matching: Pin configuration exactly matches Freightliner and Western Star factory specifications
• Vibration Resistance: Rectangular design provides secure seating in high-vibration heavy-duty diesel environments

The integrated 4-Pin connector ensures reliable electrical connection and makes installation straightforward for qualified technicians.

This product includes a 12-month warranty under the following terms:

• Coverage Period: 12-Month Worry-Free Warranty from date of purchase when installed by a fully qualified mechanic
• Eligibility: Applies to professionally installed units only — DIY or improper installation voids coverage
• Validation: Proof of professional installation on official business letterhead from your mechanic may be requested for warranty claims
• What's Covered: Manufacturing defects and material failures in the sensor assembly and integrated control unit
• What's NOT Covered: Labour charges, improper installation, failure to follow instructions, or damage from incorrect use

D2P Autoparts stands behind the durability and reliability of this NOx sensor assembly. If you experience any manufacturing issues, contact us with proof of professional installation and your original part number.

This is a high-quality aftermarket replacement part engineered by D2P Autoparts to meet or exceed OEM (Original Equipment Manufacturer) specifications for Freightliner, Western Star, and Detroit Diesel. It is 100% brand new and designed as a direct replacement for the factory NOx sensor assembly on compatible trucks.

It delivers the same emissions monitoring accuracy, electrical performance, and thermal durability as the original equipment — at a more competitive price point than an OEM Freightliner or Western Star part — without any compromise on quality, reliability, or long-term performance in heavy-duty commercial fleet service.

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

• Check Truck Model & Year: Confirm your truck is a Freightliner Cascadia (2012–2022) or Western Star 5700XE (2016–2022)
• Verify Engine Type: Confirm your truck is equipped with a Detroit Diesel DD13, DD15, or DD16 engine
• Check Electrical System: Verify your truck has a 12V electrical system (standard for both platforms)
• Match OE Part Numbers: Compare the numbers in our specifications against the part number on your original NOx sensor assembly
• Verify Connector Type: Ensure your original sensor has the 4-Pin rectangular connector with female terminals
• Check Thread Size: Confirm your mounting location uses the M20 x 1.5 thread specification
• Send Us Your VIN: Our team can verify exact fitment using your Vehicle Identification Number before you purchase

Matching the OE part number on your original NOx sensor assembly is the most reliable method to guarantee correct fitment for your specific Freightliner or Western Star truck.