Aftermarket 3000 Ppm Car NOx Sensor Nitrogen Oxide Sensor 4326874 5WK96741A 5WK96741B

The 5WK96741A is a planar dual-cell limiting current type nitrogen oxide (NOx) sensor designed for 12V medium-duty and heavy-duty diesel engine exhaust aftertreatment systems equipped with Selective Catalytic Reduction (SCR). It is an electrochemical sensor that continuously measures the concentration of nitrogen oxides (NOx) and oxygen (O₂) in the exhaust stream and communicates with the Engine Control Unit via digital CAN bus protocol. This real-time feedback enables precise control of the SCR system and ensures compliance with EPA 2010, Euro V, Euro VI, China V/VI, and equivalent emission standards.

The sensor consists of a ceramic sensor element (zirconium dioxide, ZrO₂) and an integrated electronic control unit, forming a single unit installed directly in the exhaust gas system.

The sensor is typically mounted in a vehicle's exhaust pipe, perpendicular to exhaust gas flow. Most engines equipped with SCR aftertreatment systems utilize two NOx sensors. The upstream sensor (pre-SCR) provides real-time feedback for the SCR control loop to precisely meter Diesel Exhaust Fluid (DEF) injection, while the downstream sensor (post-SCR / outlet) is used mainly to confirm that legislated emissions limits have not been exceeded. The 5WK96741A is often used as an outlet (downstream) sensor.

Important: The 5WK96741A operates on a 12V system voltage. Always verify your vehicle's electrical system voltage before purchase. Do not install on 24V systems as this will cause immediate damage to the sensor electronics.

The following part numbers are directly interchangeable with 5WK96741A. When searching for a replacement, these numbers may appear on the original sensor label, in supplier catalogs, or in vehicle manufacturer documentation. Always verify physical connector type, cable length, voltage rating, and thread size before purchasing.

From multiple supplier sources, the following cross-references have been verified:

• A listed cross-reference for 5WK96741A includes: 4326874, 2872946, 4326874RX (for comparison purposes only)

• For 5WK96741B, cross-references include: 9046013, 4326874RX/4326874, 28729846, 904-6013, 2006244, 2872946, A045S171

• The sensor is cross-referenced as 904-6013 with OE numbers 2872946, 4326874 and is a direct replacement for original equipment sensors.

• The 4326874 series (including 4326874RX) is a genuine OEM part for heavy-duty diesel applications.

• Dorman HD Solutions lists 904-6013 as a direct OE match to 4326874 and CUMMINS 2872946.

⚠️ Important: Different suffixes (5WK96741 vs. 5WK96741A vs. 5WK96741B) may indicate minor production revisions or calibration differences. Match the full alphanumeric string on your original sensor whenever possible. Do not rely solely on partial number matches. If in doubt about compatibility, refer to your original sensor's part number or consult a qualified specialist.

The 5WK96741A NOx sensor is designed for 12V commercial vehicle electrical systems and is primarily used with Cummins diesel engines in medium-duty and heavy-duty commercial vehicle applications. Application coverage spans EPA 2010, Euro V, China V/VI compliant vehicles, with primary usage in model years approximately 2013–2019.

This sensor is most closely associated with Cummins diesel engines in commercial vehicle, truck, and bus applications. It is specifically designed for SCR feedback and ECU signal output.

Based on cross-reference information and supplier listings, the 5WK96741A and its cross-references are compatible with the following engine platforms:

The 5WK96741A NOx sensor is widely used in commercial vehicles powered by Cummins diesel engines:

The 5WK96741A is specifically identified as an Outlet NOx Sensor (post-SCR / downstream position), as confirmed by multiple sources. The outlet sensor is installed after the SCR catalyst and is used to confirm that treated exhaust complies with emissions regulations.

The installation position is typically the exhaust aftertreatment outlet. The sensor is mounted in a vehicle's exhaust pipe, perpendicular to exhaust gas flow.

The 5WK96741A is designed for vehicles meeting:

• EPA 2010 (EPA10) – North American heavy-duty emissions standards (primary application)

• Euro V – European emissions standards

• China V / China VI – Asian market requirements

• Equivalent Tier standards for off-highway equipment

Due to the diversity of commercial vehicle configurations, physical fitment alone does not guarantee proper function. To confirm compatibility:

1. Check your original sensor label – Match the full part number 5WK96741A or confirmed cross-references (4326874, 2872946, 904-6013, etc.)

2. Verify voltage – The 5WK96741A is a 12V sensor; confirm your vehicle electrical system is 12V

3. Count connector pins – Black square 4-pin sealed connector

4. Confirm thread size – M20 x 1.5

5. Check engine platform – Confirm compatibility with Cummins ISX, ISX15, ISX11, ISB6.7, or L6 engines

6. Verify placement position – Typically Outlet / Downstream (post-SCR) position

7. Confirm model year – Primarily 2013–2019 vehicles

⚠️ Important note: Compatibility extends beyond physical fitment. The sensor must match the ECU's CAN communication protocol and is designed for specific engine management systems. Different vehicle manufacturers may use different calibration parameters even when the physical sensor appears identical. Always reference your original sensor part number or consult vehicle-specific documentation before purchasing.

A degraded or failed 5WK96741A NOx sensor will typically trigger one or more of the following symptoms. Early recognition can prevent secondary damage to the SCR catalyst, DEF injector, Diesel Exhaust Fluid system, or Diesel Particulate Filter.

The most common first indicator is the illumination of the check engine light on your dashboard. The ECU detects abnormal, missing, or out-of-range NOx data and triggers a fault code. A faulty NOx sensor often illuminates the vehicle's check engine light.

Common codes associated with NOx sensor failure include:

The rationality check for this sensor consists of sensor stuck low and stuck high checks performed whenever the engine operates under highly transient conditions. Faulty internal start-up behavior of the NOx sensor can cause the sensor to be evaluated as "not reliable," triggering these diagnostic codes.

When NOx readings become inconsistent or implausible, the ECU reacts to protect emissions systems by limiting torque and engine speed. Commercial vehicles may experience speed limitation or restricted RPM until the issue is resolved. This is a protective measure to prevent emissions compliance violations.

A malfunctioning NOx sensor sends inaccurate data to the ECU, which in turn adjusts the air-fuel mixture incorrectly. This imbalance often causes the engine to inject more fuel than necessary, leading to increased fuel consumption. Symptoms may also include high fuel spending.

A faulty NOx sensor disrupts the ECU and SCR, triggering fault codes and leading to incorrect DEF dosing. False high NOx readings cause the SCR to over-dose DEF, resulting in rapid AdBlue depletion and potential crystallized injector. This is one of the most costly indirect symptoms of a failing NOx sensor.

A failing NOx sensor can result in erratic or unstable idling as the ECU compensates for inappropriate readings. The engine may run lean or rich, causing instability at idle and under load. Erratic or unstable idling is a common sign of a faulty NOx sensor. You may also notice sudden jolts or a jerky idle.

A defective NOx sensor can result in improper combustion, leading to visible smoke from your exhaust. This is not only a performance issue but can also lead to failed emissions tests.

Since the NOx sensor directly impacts your vehicle's emissions, a failure can cause your vehicle to exceed acceptable limits, resulting in a failed test. The SCR system may fail to maintain compliance with emission testing requirements.

A failing NOx sensor can cause difficulty starting when the engine is cold. Inaccurate NOx readings may prevent proper SCR initialization during cold starts.

If the internal heater fails (open circuit), the sensor never reaches operating temperature, and DTCs set immediately after cold start. The heater circuit is critical for bringing the sensing element to operational temperature quickly after engine startup, especially in cold ambient conditions.

Before replacing the 5WK96741A, perform these basic checks:

1. Visual inspection – Look for damaged cable insulation, chafing against chassis components, bent pins, or a melted/cracked connector. Soot build-up and moisture ingress are common reasons for NOx sensor failure.

2. Check DTC status – Using a diagnostic scan tool (OBD-II/SAE J1939 compatible), verify which codes are present and whether they are active or intermittent.

3. Monitor live values – Observe sensor readings during engine operation. When the NOx sensor is unable to maintain a reliable output, its signal quality will be set to "not reliable."

4. Heater resistance test – Measure between heater positive and heater ground pins using a multimeter. An open circuit or short indicates internal failure.

5. Voltage supply – With key on and engine off, verify 12V power at the sensor connector (do NOT apply 24V).

6. Live data review – Observe NOx readings; a fixed reading of 0 ppm or pegged at maximum without change points strongly suggests a faulty sensor.

Note: A recurring NOx sensor code may also be caused by an exhaust leak upstream of the sensor, poor DEF quality, a failed DEF injector, a contaminated SCR catalyst, or communication issues on the vehicle's CAN network. Perform a thorough system diagnosis before sensor replacement to avoid repeat failures.

Purchasing the correct 5WK96741A NOx sensor and installing it properly is essential for reliable SCR performance and avoiding costly mistakes. Commercial vehicle operators should pay special attention to voltage compatibility, correct identification of part numbers, and installation procedures.

• Match the full number on your original sensor – 5WK96741A or confirmed cross-references (4326874, 2872946, 904-6013, 28729846, 2006244, A045S171)

• Check for suffix variations – Different suffixes (5WK96741 vs. 5WK96741A vs. 5WK96741B) may indicate minor production revisions or calibration differences

• Avoid "universal fit" listings – The 5WK96741A is a specific digital device; generic sensors claiming to fit "all diesels" are unlikely to communicate correctly with your ECU

• Check OE numbers carefully – Refer to the part number on the back of the old unit; if in doubt about compatibility, consult a specialist

• Always ensure the replacement sensor matches the original part numbers for compatibility

• Reputable supplier – Choose a supplier with documented quality control and a minimum 6–12 month warranty. Many premium suppliers offer 12-month, unlimited mileage coverage.

• Avoid used or "remanufactured" – NOx sensors degrade internally from heat and contamination. Used sensors almost always fail prematurely. Look for 100% new products.

• Price guideline – Authentic quality replacements typically range from approximately $90 to $210. Suspiciously low prices (below $60) may indicate counterfeit or defective products.

• Packaging – New sensors should be shipped in protective packaging with a protective cap over the ceramic tip

• Direct replacement – Ensure the replacement sensor matches the function and performance of the original sensor. Dorman HD Solutions specifically lists 904-6013 as a direct replacement that properly restores nitrogen oxide detection to comply with emissions regulations.

• Aftermarket options – For aftermarket options such as AS-PL (NOX9108) and Dinex (5EL005), ensure compatibility with your specific vehicle application.

• Do not touch the ceramic sensing tip – Skin oils cause thermal shock cracking during the first heat-up cycle

• Inspect cable routing – Ensure the new cable follows the original path, using existing clips and standoffs. Avoid sharp bends or contact with moving parts

• Remove protective cap only when ready – Keep the sensor clean by removing the protective cap immediately before installation. Do not allow any dirt to contaminate the threads

• Clean the bung threads – Use a thread chaser (M20 x 1.5) to remove carbon buildup and rust before installation

• Inspect electrical connections – Check the vehicle-side connector for cleanliness, corrosion, and sealing integrity before installing the new sensor

Follow this sequence for proper installation:

1. Prepare the mounting location – Allow the exhaust system to cool before removal. Wear heat-resistant gloves and eye protection

2. Remove the old sensor – Carefully remove the faulty sensor from the exhaust bung

3. Inspect the vehicle connector – Ensure the mating connector is dry, clean, and free from corrosion

4. Remove protective cap – Immediately before installation, remove the protective cover from the sensor probe

5. Install the probe – Insert the sensor probe into the exhaust bung. Hand-tighten while holding the sensor body to prevent cable twisting

6. Torque properly – Follow manufacturer specifications for tightening torque. Typical torque for M20 x 1.5 threads is 40–60 Nm. Over-tightening can damage the threads or bung; under-tightening can cause exhaust leaks

7. Connect the harness – Connect the mating 4-pin connector to the sensor. Ensure the connector interior is clean and dry

8. Secure the cable – Use original routing clips and standoffs to secure the harness away from heat sources and moving parts

9. Easy installation – The sensor is engineered for easy installation, integrating seamlessly into the vehicle's exhaust system

A new NOx sensor will NOT function correctly until the ECU learns its baseline values and performs a plausibility check. Many returns are caused by skipped adaptation, not a defective part.

Why adaptation is necessary: Engine Control Units continuously learn and adapt to sensor degradation over time. Installing a fresh component without resetting these learned values leaves your ECU operating on outdated, skewed data. When repairing the aftertreatment system, both sensors should be replaced to ensure they are working in sync.

What DOES NOT work: Attempting to clear deep-level adaptation memory by disconnecting the battery is ineffective on modern emissions systems and often triggers secondary Battery Management System faults.

Recommended procedure:

1. Install the sensor following the sequence above

2. Connect a professional diagnostic scan tool capable of commercial vehicle diagnostics (SAE J1939 / OBD-II compatible)

3. Clear all existing DTCs – Use the diagnostic tool to clear all existing fault codes

4. Perform "NOx sensor reset / adaptation / teach-in" – This function is typically found under "Special functions," "SCR system," or "Aftertreatment service" in diagnostic software. The ECU may command a specific warm-up sequence

5. Reset SCR learned values (if available) – This clears previously stored efficiency values from the old sensor

6. Drive cycle – Complete a 15–20 minute mixed driving cycle at operating temperature with varying engine loads

7. Verify readiness – After the drive cycle, check for any returning DTCs. Monitor live NOx data; it should fluctuate logically

Without proper adaptation, you may still see DTCs (e.g., P2200, P229E) even with a brand new sensor. Many returns are caused by skipped adaptation, not a defective part. The sensor should be replaced and reset/adapted using an appropriate diagnostic tool.

• 12V system confirmation: Unlike many other 5WK96xxx series NOx sensors that operate on 24V, the 5WK96741A is a 12V sensor. Verify your vehicle's electrical system voltage before purchase.

• Outlet position identification: The 5WK96741A is typically used as an outlet (post-SCR) sensor. Verify which position (upstream vs. downstream) requires replacement on your specific vehicle.

• Wiring harness condition: Commercial vehicles operate in harsh environments (vibration, heat, moisture, road salt). Inspect the full harness length for chafing, corrosion at connectors, and damaged insulation before condemning the sensor.

• SCR system health: A recurring NOx sensor code may indicate a failed SCR catalyst, DEF quality issues, or a clogged DEF injector. These should be diagnosed before replacing the sensor a second time.

• Multiple sensor positions: Some platforms use two NOx sensors (upstream and downstream). When repairing the SCR system, it is often recommended to replace both sensors to ensure they are working in sync.

• ECU software updates: In some cases, a recurring NOx sensor issue may be addressed by an ECU software update rather than repeated sensor replacement.

• Root cause investigation: Soot build-up is the most common reason for NOx sensor failure, but moisture can also damage the sensors. Always address the root cause before replacement to avoid repeat failures.

• In regions with mandatory emissions testing (EU, California, China, Australia, Brazil), a non-functioning NOx sensor will cause the MIL to illuminate, resulting in automatic inspection failure

• It is illegal to defeat, delete, or simulate the NOx sensor signal in any on-road vehicle. Always replace with a fully functional sensor

• Commercial fleets subject to emissions auditing must maintain properly functioning SCR systems, including accurate NOx sensing

• A properly functioning NOx sensor is critical for passing state-mandated emissions inspections

• Before purchasing, confirm the supplier offers a return or exchange for compatibility errors, preferably within 30 days of receipt

• Keep your original sensor until the new one is confirmed working – it serves as the ultimate reference for part number and fitment

• Request a data sheet or installation guide that includes pinout and adaptation steps if available

• Most reputable suppliers offer a 6–12 month warranty against manufacturing defects

The NOx Sensor 5WK96741A is a critical emissions aftertreatment component for 12V medium-duty and heavy-duty diesel commercial vehicles. Unlike many other sensors in the 5WK96xxx series which operate on 24V, the 5WK96741A is specifically designed for 12V systems and is primarily used with Cummins diesel engines (ISX 11.9L/15L, ISB6.7) in Freightliner, Kenworth, Peterbilt, International, and Western Star commercial vehicle applications, meeting EPA 2010 and Euro V emission standards.

Key cross-references: 5WK96741, 5WK96741B, 4326874, 4326874RX, 2872946, 28729846, 904-6013, 2006244, A045S171, 2871974, 9046013, NOX9108, 5EL005

Key technical specifications:

• Operating voltage: 12V DC (critical distinction – NOT 24V)

• NOx measuring range: 0–3000 ppm

• Response time: Sub-second for precise SCR control

• Connector: Black square 4-pin sealed

• Thread: M20 x 1.5

• Torque specification: 40–60 Nm

• Weight: Approximately 0.3 kg – 0.6 kg

• Package dimensions: 18 * 11 * 6 cm

• Emission standard: EPA10, Euro V

• Certifications: CE, TS16949, ISO14001, IATF16949

Compatible engine platforms:

• Cummins ISX / ISX15 / ISX11 (11.9L – 15L heavy-duty diesel)

• Cummins ISB6.7 (6.7L medium-duty diesel)

• Cummins L6 (11.9L inline-6)

• Cummins ISBe / ISC / ISL

Vehicle applications (representative):

• Freightliner (Cascadia, M2, etc.) – 2013–2019

• Kenworth (various models) – 2013–2019

• Peterbilt (384, 387, various) – 2013–2019

• International (various models) – 2013–2019

• Western Star – 2013–2019

• Crane Carrier Low Entry L6 11.9L ISX – 2016

Placement on vehicle: The 5WK96741A is identified as an Outlet NOx Sensor, installed after the SCR catalyst (exhaust aftertreatment outlet). The sensor is mounted in the exhaust pipe perpendicular to exhaust gas flow.

Installation requirements:

• Do NOT apply anti-seize to threads

• Do NOT touch ceramic sensing element

• Confirm 12V system voltage – DO NOT install on 24V vehicles

• Professional installation and mandatory ECU adaptation required after replacement

• Perform torque to 40–60 Nm (M20 x 1.5 threads)

• Always perform root cause investigation before replacement – soot build-up and moisture ingress are common causes of failure

CRITICAL NOTE – VOLTAGE COMPATIBILITY: The 5WK96741A operates on 12V DC. This distinguishes it from many other NOx sensors in the 5WK96xxx series that are designed for 24V commercial vehicle applications. Always verify your vehicle's electrical system voltage (12V or 24V) before purchase. Installing this 12V sensor on a 24V system will cause immediate heater or electronics damage.

CRITICAL NOTE – ECU ADAPTATION IS MANDATORY: A physical NOx sensor replacement must be paired with an ECU adaptation or reset to clear permanent fault codes and restore SCR efficiency. Disconnecting the battery will NOT work. Without proper adaptation, you will still see DTCs (P2200, P229E) even with a brand new sensor. Many returns are caused by skipped adaptation, not a defective part.

Self-diagnostic technology: The sensor integrates advanced self-diagnostic function that automatically compensates for minor signal drifts and environmental variations, maintaining high-precision NOx concentration detection and consistent output over time.

Proper selection (matching the part number 5WK96741A and confirmed cross-references), confirmation of 12V system voltage, careful installation using correct torque (40–60 Nm), and mandatory ECU adaptation ensure full emissions compliance, optimal fuel economy, and reliable SCR system performance. Use this guide to confidently purchase and replace a failed 5WK96741A NOx sensor without compatibility issues or repeat failures.

For further technical support, refer to your engine or vehicle manufacturer's service documentation or consult a qualified diesel emissions specialist.