High-Quality OEM Replacement Outlet NOx Sensor

This outlet NOx sensor is engineered for Mercedes-Benz vehicles equipped with Detroit Diesel engines. This is an outlet position sensor specifically designed for emissions monitoring on diesel powertrains.

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

A NOx (Nitrogen Oxide) sensor is a precision emissions monitoring device that detects nitrogen oxide levels in the exhaust stream. On diesel engines, particularly those in Mercedes-Benz vehicles, the NOx sensor performs several critical functions:

• Emissions Monitoring: Continuously measures nitrogen oxide concentration in exhaust gases to ensure compliance with emissions standards
• SCR System Control: Provides data to the Selective Catalytic Reduction (SCR) system to optimize injection of DEF (Diesel Exhaust Fluid) for proper NOx reduction
• Engine Management: Relays real-time emissions data to the engine control module (ECM) for combustion optimization and efficiency
• Diagnostic Validation: Enables the vehicle to self-diagnose emissions system health and trigger warning lights if problems are detected

A properly functioning NOx sensor is essential for diesel engine performance, environmental compliance, and vehicle diagnostics.

Common symptoms of a worn or failing outlet NOx sensor on Mercedes-Benz diesel vehicles include:

• Check engine light or emissions warning light illuminated on the dashboard
• Diagnostic trouble codes related to NOx sensor circuit (P240x series codes) stored in engine memory
• Reduced engine performance or limp-mode activation — limiting vehicle speed or power delivery
• Excessive DEF consumption or faulty DEF system warnings
• Rough idle or hesitation during acceleration
• Failed emissions testing or emissions system faults reported during diagnostics
• Loss of fuel economy efficiency

If any of these symptoms appear, have your vehicle scanned with a diesel-capable diagnostic tool immediately to prevent engine damage or emissions system failure.

Diesel emissions systems with SCR (Selective Catalytic Reduction) typically use two NOx sensors positioned at different points in the exhaust stream:

• Inlet NOx Sensor: Positioned upstream before the SCR catalyst. Measures baseline nitrogen oxide levels entering the SCR system to determine how much DEF should be injected
• Outlet NOx Sensor: Positioned downstream after the SCR catalyst. Measures nitrogen oxide levels exiting the SCR system to verify the catalyst is functioning properly and reducing NOx emissions to acceptable levels

This outlet sensor validates that your SCR catalyst is working correctly. A failing outlet NOx sensor can trigger false emissions warnings even if your SCR system is functioning normally. Always verify which position sensor you require before ordering — inlet and outlet sensors are NOT interchangeable.

This listing includes:

• 1x Outlet NOx Sensor — Outlet Position, ready for immediate installation

This is the outlet position sensor only. If you also require an inlet NOx sensor, please check our store for the corresponding listing. The sensor includes the connector assembly and mounting hardware for direct installation.

While some experienced DIY mechanics may attempt sensor replacement, professional installation by a qualified diesel technician is strongly recommended. NOx sensor replacement requires:

• Proper disconnection and reconnection of high-temperature exhaust system components
• Careful handling of precision sensor elements to prevent damage
• Knowledge of correct installation orientation and mounting position
• Engine diagnostic scanning to clear fault codes and verify sensor integration
• DEF system verification and recalibration on some model years
• Professional installation is required to validate warranty coverage

Incorrect installation can result in false emissions warnings, SCR system malfunction, or limp-mode activation. Note: Installation instructions are not included with this product.

Yes — professional diagnostic verification is essential after installing a new NOx sensor. Your technician should:

• Clear Fault Codes: Use a diesel-capable diagnostic scanner to clear all stored emissions fault codes from engine memory
• System Verification: Monitor live NOx readings to confirm the new sensor is communicating correctly with the engine control module
• SCR Validation: Verify that the SCR system is responding appropriately to sensor data and DEF injection is functioning
• Test Drive: Complete a test drive with diagnostic monitoring to confirm no new faults develop
• Final Scan: Re-scan the vehicle to ensure all systems are functioning and no diagnostic codes recur

Professional diagnostic work validates proper sensor integration and protects your investment in this component.

NOx sensor lifespan varies depending on operating conditions:

• Typical Service Life: Most OEM NOx sensors last 80,000 to 120,000 miles under normal operating conditions
• High-Mileage Vehicles: Some sensors may require replacement earlier on vehicles driven in severe duty cycles or with frequent towing
• Fuel Quality Impact: Diesel fuel quality significantly affects sensor lifespan — higher sulfur content or contaminated fuel accelerates sensor degradation
• Preventive Replacement: Many technicians recommend proactive NOx sensor replacement during major service intervals to prevent emissions system failure

Regular maintenance, quality fuel, and timely filter changes extend NOx sensor lifespan and help prevent emissions system problems.

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

• Eligibility: Warranty applies when the product is installed by a fully qualified professional diesel technician
• Verification: Formal letter on business letterhead from a licensed mechanic confirming professional installation is required for warranty claims
• Coverage: Covers manufacturing and sensor defects on the component itself only — labour costs and diagnostic charges are excluded
• Exclusions: Does not cover sensor failure resulting from incorrectly fitted parts or failure to follow proper installation instructions

If you experience any product-related issue within the warranty period, contact us with proof of professional installation and your original part number to initiate a claim.

This is a high-quality aftermarket replacement part engineered to meet or exceed Mercedes-Benz and Detroit Diesel OEM (Original Equipment Manufacturer) specifications. It is 100% brand new and designed as a direct replacement for the factory outlet NOx sensor on compatible Mercedes-Benz diesel vehicles.

It delivers the same precision sensing capability, electrical characteristics, and emissions monitoring accuracy as the original equipment — at a more competitive price point than a Mercedes-Benz genuine part — without compromising on quality or long-term reliability in demanding diesel operating environments.

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

• Check Vehicle Platform: Confirm your vehicle is a Mercedes-Benz equipped with a Detroit Diesel engine
• Verify Emissions System: Confirm your vehicle has an SCR (Selective Catalytic Reduction) emissions system with dual NOx sensors
• Confirm Sensor Position: This is the OUTLET position sensor (downstream of the SCR catalyst) — ensure you require the outlet sensor, not the inlet
• Match OE Part Numbers: Compare the numbers in our specifications against the part number on your original outlet NOx sensor
• Check Connector Type: Verify the connector type matches your vehicle's electrical system
• Send Us Your VIN: Our team will confirm exact fitment using your Vehicle Identification Number before you purchase

Matching the OE part number on your original sensor is the most reliable method to guarantee correct fitment for your specific Mercedes-Benz diesel vehicle.