Ecodiesel HTCC Auto NOx Sensor 4326872 4326872RX 1954664PRX

The 5WK96749A is a planar dual-cell limiting current type nitrogen oxide (NOx) sensor designed for 12V 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, and equivalent emission standards.

The sensor is a CES (Controlled Emission System) GEN 2.8 design manufactured to Continental specifications, offering improved measurement accuracy and faster response compared to earlier generation sensors. The sensor operates by measuring the level of oxygen in the exhaust gas before and after the ceramic element; the difference between the two measurements is used to calculate the level of NOx present.

Important: The 5WK96749A operates on a 12V system voltage. Always verify your vehicle's electrical system voltage before purchase. Do not install on 24V systems — this will cause immediate and permanent damage to the sensor electronics.

The following part numbers are directly interchangeable with 5WK96749A and its variants. 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, voltage rating, thread size, and cable length before purchasing.

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

• The 5WK96749A sensor is listed as direct replacement for OEM numbers 4326872, 4326872RX, 2872942, 2872942NX, 2520640C1, 1924000, 904-6015, A045S169, and others.

• A supplier cross-reference list confirms that 5WK96749B, 4326872, 4326872RX, 2872942, and 2872942NX are all interchangeable within this sensor family.

• The sensor is cross-referenced with 5WK96749A, 5WK96749B, 4326872, 4326872RX, 2872942, 2872942NX, 2520640C1, 1924000, 904-6015, A045S169 for heavy-duty diesel applications.

• An Amazon listing identifies the 5WK96749B as an outlet sensor for 2013–2018 Cummins ISX 15.0 and ISX 11.9 engines, replacing 2872942, 904-6015, and 4326872.

• A new-for-Cummins NOx sensor interchange list includes 2872942NX, 4326872RX, 2520640C1, 5WK96749B, and 1924000.

⚠️ Important: Different suffix variations (5WK96749 vs. 5WK96749A vs. 5WK96749B) 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. All cross-reference numbers are for identification purposes only — the underlying Continental reference number is the most reliable way to ensure correct functionality.

The 5WK96749A NOx sensor is designed for 12V commercial vehicle electrical systems and is primarily used with Cummins diesel engines in heavy-duty and medium-duty commercial vehicle applications. Application coverage spans EPA 2010 / Euro V compliant vehicles, with primary usage in model years approximately 2013–2020.

This sensor is most closely associated with Cummins diesel engines in heavy-duty truck and commercial vehicle applications. It is specifically designed for use with Cummins engines fitted with SCR aftertreatment systems meeting EPA 2010 emission standards. The sensor is tailored specifically for Continental 12V systems, ensuring optimal performance in Cummins engines.

Based on cross-reference information and supplier listings, the 5WK96749A is compatible with the following engine platforms:

The sensor is designed specifically for Cummins engines, ensuring enhanced engine performance and optimal emission control.

The 5WK96749A NOx sensor is widely used in heavy-duty trucks powered by Cummins diesel engines, including (but not limited to):

Source: Verified from multiple compatibility listings including eBay, Amazon, and aftermarket supplier data.

The 5WK96749A is specifically identified as an Outlet / Output NOx Sensor in most applications. The outlet sensor is installed after the SCR catalyst (downstream / post-SCR position) and is used to confirm that treated exhaust complies with emissions regulations.

When replacing this sensor, verify the position of your failed sensor:

• Upstream (inlet / pre-SCR) — mounted before the DPF or SCR catalyst

• Downstream (outlet / post-SCR) — mounted after the SCR catalyst (this sensor)

The 5WK96749A is designed for vehicles meeting:

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

• Euro V — European emissions standards

• Equivalent Tier standards for on-road and off-highway equipment

The sensor meets EPA and EU emissions standards, ensuring legal operation across regulated markets.

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 5WK96749A or confirmed cross-references (5WK96749B, 4326872, 2872942, 2520640C1, 904-6015, etc.)

2. Verify voltage — The 5WK96749A is a 12V sensor; confirm your vehicle electrical system is 12V

3. Count connector pins — 4-pin sealed connector (female square; (4) male blade terminals)

4. Confirm thread size — M20 x 1.5

5. Check engine platform — Confirm compatibility with Cummins ISX 15.0, ISX 11.9, X15, or ISB 6.7 engines

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

7. Confirm model year — Primarily 2013–2020 vehicles

8. Check the original OE number — OEM part numbers are located on the back of the old unit. If in doubt about compatibility, refer to your original sensor's part number before purchasing.

⚠️ Important note: Compatibility extends beyond physical fitment. The sensor must match the ECU's CAN communication protocol. Always reference your original sensor's part number or consult vehicle-specific documentation before purchasing.

A degraded or failed 5WK96749A 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.

If you have performed an on-board computer scan and your vehicle is showing any of the following error codes, it typically means the NOx sensor has failed.

The rationality check for this sensor consists of sensor stuck low and stuck high checks performed whenever the engine operates under highly transient conditions. A fault condition is reached whenever the NOx sensor values are below or above a fault limit.

When NOx readings become inconsistent or implausible, the ECU reacts to protect emissions systems by limiting torque and engine speed. Vehicle owners may experience reduced engine power, sluggish acceleration, and overall poor vehicle performance. Failed sensors can trigger limp mode, DEF warnings, power restriction countdowns, or prevent restart.

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 and higher operating costs.

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 DEF depletion and potential crystallized injector. This is one of the most costly indirect symptoms of a failing NOx sensor.

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. Failing to maintain a healthy NOx sensor can result in non-compliance, potentially leading to fines and penalties.

The OBD monitor is designed to detect bad sensor quality. The function monitors the time from enable command sent (sensor allowed to heat itself) to the time when the sensor reports full readiness. If the time is too long, the sensor does not fulfill the requirements.

Before replacing the 5WK96749A, perform these basic checks:

1. Visual inspection — Look for damaged cable insulation, chafing against chassis components, bent pins, or a melted/cracked connector

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 confirmed

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

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

5. 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, or a contaminated SCR catalyst. Perform a thorough system diagnosis before sensor replacement to avoid repeat failures.

Purchasing the correct 5WK96749A 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, placement position, and installation procedures.

• Match the full printed number on your original sensor — 5WK96749A or confirmed cross-references (4326872, 2872942, 2520640C1, 904-6015, 1924000, A045S169, etc.)

• Check suffix variations — Different suffixes (5WK96749 vs. 5WK96749A vs. 5WK96749B) may indicate minor production revisions or calibration differences. Do not rely solely on partial number matches

• Check OE numbers carefully — OEM part numbers are located on the back of the old unit. If in doubt about compatibility, refer to your original sensor's part number before purchasing

• All cross-reference numbers are for identification purposes only — The underlying Continental reference number is the best way to ensure correct functionality. Any mention of OEM names or OEM product ID numbers is intended for identification purposes only

• Reputable supplier — Choose a supplier with documented quality control and a minimum 12-month warranty. Premium suppliers may offer one-year, 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 $66 to $373:

  • Economy/aftermarket (8-wire ISB variant): $66–$95

  • Standard aftermarket: $125–$160

  • Premium aftermarket: $216–$373

  • Suspiciously low prices (below $50) may indicate counterfeit or defective products

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

• Third-party testing — Look for sensors that have been tested and accredited by third parties, with fit-and-forget re-flashable software for future compatibility

• After-sales service — Some suppliers offer one-for-one compensation in case of manufacturing defects

• 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

• Verify connector style — Confirm the connector is a female square connector with (4) male blade terminals before installation

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 — Critical: Follow OEM torque specifications. Typical torque for M20 x 1.5 threads: 40–55 Nm. Torque specifications are critical as over-tightening cracks exhaust bungs while under-tightening causes leaks

7. Connect the harness — Connect the mating 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

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.

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

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

6. If using a future-proof sensor — Some GEN 2.8 sensors feature software re-flashing capability for future compatibility with OE software updates

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

8. Verify readiness — After the drive cycle, check for any returning DTCs. Monitor live NOx data; it should fluctuate logically (higher readings under heavy load, lower readings at idle)

⚠️ 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.

• 12V system confirmation: Unlike many other 5WK96xxx series NOx sensors that operate on 24V, the 5WK96749A is a 12V sensor. Verify your vehicle's electrical system voltage before purchase. Installing a 12V sensor on a 24V system will cause immediate heater or electronics damage

• Outlet position verification: The 5WK96749A is identified as an Outlet / Downstream (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

• 8-wire variant: For ISB engine applications, the sensor may be supplied with 8 wires — confirm wire count matches your original sensor

• Future-proof technology: Some GEN 2.8 sensors feature third-party tested OE-level accuracy and reactivity, improved dust and water protection, and re-flashable software for future ECU compatibility

• 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

• The sensor is designed to optimize emissions and fuel economy to meet national and regional emission standards

• The sensor meets EPA and EU emissions standards, ensuring legal operation across regulated markets

• 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. Some offer one-year, unlimited mileage coverage

Based on compatibility data, the 5WK96749A sensor family is primarily used for vehicles from model years approximately 2013 through 2020 for Cummins ISX 15.0, ISX 11.9, and X15 engine platforms. Specific compatibility notes include:

• 2013–2018 Cummins ISX 15.0 and ISX 11.9 — Primary application

• 2020 Freightliner Cascadia with 14.9L engine — Compatible

• 2013–2019 International Harvester — 5900i, 7600, 8600 TranStar, 9900i, HX515, HX520, HX615

Always verify your specific vehicle model year and engine platform before purchase. For newer vehicles, always reference your original sensor's part number as OEM specifications may have changed.

The NOx Sensor 5WK96749A is a critical emissions aftertreatment component for 12V heavy-duty diesel commercial vehicles. As a CES GEN 2.8 sensor, it offers advanced HTCC ceramic sensing technology for improved measurement accuracy and response speed.

Key cross-references: 5WK96749B, 4326872, 4326872RX, 2872942, 2872942NX, 2872942RX, 2520640C1, 1924000, 904-6015, 1954664PE, 1954664PRX, A045S169, P4326869, SNS149B

Key technical specifications:

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

• Generation: CES GEN 2.8

• NOx measuring range: 0–2500 ppm

• O₂ measuring range: 0%–21%

• NOx accuracy: 0–100ppm: ±10ppm; 100–500ppm: ±10%; 500–1500ppm: ±15%; 1500–2500ppm: ±25%

• O₂ accuracy: 0%–5%: ±0.2%; 5%–21%: ±4%

• Response time: t10↔90% λlin < 3500 ms; t10↔90% NOx < 3500 ms

• Light-off time: < 100 seconds (from dew point)

• Design life: 6,000 hours or 350,000 km

• Connector: Female square; (4) male blade terminals; 22 GA wire gauge

• Thread: M20 x 1.5

• Torque specification: 40–55 Nm

• Emission standard: EPA10, Euro V

• Certifications: TS16949, CE, CCC, ISO14001, IATF16949

Compatible engine platforms:

• Cummins ISX 15.0 (2013–2018)

• Cummins ISX 11.9 (2013–2018)

• Cummins X15 (2020)

• Cummins ISB 6.7 (8-wire variant)

Vehicle applications (representative):

• Freightliner: Cascadia, Columbia, Coronado (2013–2020)

• Kenworth: T660, T680, T700, T800, T880, W900

• Peterbilt: 365, 367, 384, 386, 388, 389, 567

• International: ProStar, HX series, LT series (2013–2019)

• Western Star: 4900, 6900 series

• Volvo: VNL

Placement on vehicle: The 5WK96749A is identified as an Outlet / Downstream NOx Sensor, installed after the SCR catalyst (post-SCR position) to verify emissions compliance.

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 40–55 Nm

• Verify connector configuration (female square; 4 male blade terminals; 22 GA wire gauge)

• For ISB applications, confirm 8-wire configuration

• Use M20 x 1.5 thread chaser to clean bung threads

CRITICAL NOTE – VOLTAGE COMPATIBILITY: The 5WK96749A 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.

Failure symptoms summary:

• Check engine light illumination

• Diagnostic codes: P2200, P2201, P2202, P2203, P229E, P229F, U029E, P20EE

• Reduced engine power / limp mode / power derate

• Poor fuel economy / increased fuel consumption

• Increased DEF (AdBlue) consumption

• Failed emissions test

• Signal reliability issues and OBD monitor faults

Proper selection (matching the part number 5WK96749A and confirmed cross-references), confirmation of 12V system voltage, careful installation using correct torque (40–55 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 5WK96749A NOx sensor without compatibility issues or repeat failures.