Meta Description: WJIECO 4326872 NOx Sensor (also 4326872RX / A045S169) — direct-fit replacement for Cummins ISX12 ISX15 6.7L diesel engines. IATF 16949 certified, fast shipping, 12-month warranty. Fix SCR emission faults today.
What Is the 4326872 Nitrogen Oxide Sensor?
The 4326872 NOx sensor (also referenced as 4326872RX and A045S169) is a critical exhaust aftertreatment component designed for Cummins heavy-duty diesel engines. Mounted at the outlet position of the SCR (Selective Catalytic Reduction) system, this sensor measures nitrogen oxide (NOx) levels in the exhaust stream and sends real-time data to the engine ECU.
WJIECO’s aftermarket 4326872 nitrogen oxide sensor delivers OEM-equivalent accuracy and durability at a fraction of the dealer price. Built with advanced multi-layered ceramic sensing elements sintered at 1500°C, it ensures precise NOx readings for proper DEF dosing and EPA emissions compliance.
Cross Reference Part Numbers
Before ordering, verify your original part number matches one of these OE cross-references:
表格
| Cross Reference Number | Brand / Type |
|---|---|
| 4326872 | Cummins OEM |
| 4326872RX | Cummins Remanufactured |
| 4326872NX | Cummins NOx Sensor |
| A045S169 | Continental / OEM Supplier |
| 2872942 | Cummins Earlier Version |
| 2872942NX | Cummins NOx |
| 1954664 | International / Navistar |
| 2520640C1 | International Truck |
| 5WK9 6749B | Continental Sensor Code |
| A2C95992000-01 | VDO / Continental |
💡 WJIECO Tip: Always match your original OE number first. If unsure, send us your VIN or engine serial number and we’ll confirm fitment within 24 hours.
Vehicle & Engine Compatibility
The WJIECO 4326872 NOx sensor is engineered as a direct replacement for the following applications:
Cummins Engines
- ISX12 — 2011–2018 model years
- ISX15 — 2011–2018 model years
- QSX15 — Industrial & heavy-duty applications
- ISB 6.7L — Mid-range diesel engines
- MX13 — PACCAR MX-13 engines
Truck Brands & Models
- Kenworth — T680, T880, W900 (with Cummins ISX)
- Peterbilt — 579, 389, 567 (with Cummins ISX)
- International / Navistar — ProStar, LoneStar, LT Series
- Freightliner — Cascadia, Coronado (Cummins-powered)
- Volvo / Mack — Selected models with Cummins ISX option
Position: Outlet / Downstream of SCR catalyst
System: SCR (Selective Catalytic Reduction) aftertreatment
Voltage: 12V / 24V system compatible
Common Symptoms of a Failing 4326872 NOx Sensor
A faulty outlet NOx sensor can trigger a cascade of drivability and emission issues. Watch for these warning signs:
🔴 Check Engine Light (CEL) & Fault Codes
- SPN 3226 / FMI 1, 2, 4 — NOx Sensor Outlet Signal Fault
- SPN 4364 — NOx Sensor Rationality Error
- P2201 — NOx Sensor Circuit Range/Performance
- P229F — NOx Sensor 2 Circuit Low
- Derate codes — Engine power reduction after 5-hour countdown
🚚 Drivability Issues
- Engine derate (power limitation to 55 mph or lower)
- Poor fuel economy and reduced throttle response
- Frequent or failed regeneration cycles
- DEF consumption abnormalities (too much or too little)
⚠️ Emission & Compliance Problems
- Failed emissions test / DOT inspection
- SCR system efficiency faults
- DEF quality sensor errors (secondary)
If you’re experiencing any of these symptoms, replacing your 4326872 NOx sensor with a WJIECO unit can restore full engine performance and eliminate derate conditions.
WJIECO 4326872 NOx Sensor — Technical Specifications
表格
| Parameter | Specification |
|---|---|
| Part Number | WJIECO-NOX-4326872 |
| OE Reference | 4326872 / 4326872RX / A045S169 |
| Sensor Type | NOx (Nitrogen Oxide) Sensor, Outlet |
| Measuring Range | 0–2500 ppm NOx |
| O₂ Range | 0–21% |
| Accuracy | ±10 ppm ~ ±30% of reading (no ammonia interference) |
| Ready Time | 120–165 seconds |
| NOx Response Time | ≤ 4000 ms |
| Probe Temperature | -40°C ~ +850°C (short-term peak) |
| Continuous Temp | 200°C ~ +800°C |
| Thread Size | M20 × 1.5 |
| Installation Torque | 50 ± 10 N·m |
| Communication | CAN 2.0B (250 kbps), SAE J1939 |
| Protection Rating | IP6K9K |
| Housing Material | High-strength aluminum control module |
| Cable Length | OEM exact match (varies by application) |
| Connector | 5-pin OEM matching plug |
| Certification | IATF 16949, ISO 9001 |
Why Choose WJIECO for Your 4326872 NOx Sensor?
1. OEM-Equivalent Performance, Not OEM Price
WJIECO NOx sensors are built with the same multi-layered ceramic sensing technology as the original Continental unit. Our sensing elements are sintered at 1500°C for maximum durability and measurement precision — matching OEM accuracy specs at 40–60% less cost.
2. IATF 16949 Certified Manufacturing
Every WJIECO 4326872 nitrogen oxide sensor is produced in an IATF 16949 certified facility with full traceability from raw material to finished product. Each unit undergoes 100% functional testing including high-temperature aging and vibration simulation before shipment.
3. Direct Plug-and-Play Installation
No splicing, no programming, no calibration needed. Our 4326872RX replacement sensor comes with the exact OEM connector pinout, cable length, and thread pitch. Simply remove the old sensor and install the WJIECO unit — your ECU will recognize it immediately.
4. Built for Heavy-Duty Environments
Trucking is tough. That’s why WJIECO NOx sensors feature:
- IP6K9K high-pressure washdown protection
- Vibration and thermal shock resistance
- Corrosion-resistant stainless steel probe
- Reinforced cable braiding for undercarriage durability
5. 12-Month Hassle-Free Warranty
We stand behind our products. Every WJIECO 4326872 sensor comes with a 12-month replacement warranty and dedicated technical support. If you encounter any fitment or performance issues, our team responds within 24 hours.
Installation Guide & Best Practices
⚠️ Safety First
- Allow exhaust system to cool completely before starting — exhaust components can exceed 500°C and cause severe burns.
- Wear safety glasses and heat-resistant gloves.
- Disconnect the negative battery terminal before unplugging the sensor connector.
Step-by-Step Installation
- Locate the sensor — mounted on the exhaust pipe downstream of the SCR catalyst box (outlet position).
- Disconnect the electrical connector — release the locking tab and gently pull apart.
- Remove the old sensor — use a 22mm NOx sensor socket or wrench. Apply penetrating oil if seized.
- Inspect the mounting bung — clean any carbon buildup or corrosion from the threads.
- Apply anti-seize compound — lightly coat the sensor threads (do not get anti-seize on the sensing tip).
- Install the WJIECO sensor — thread in by hand first, then torque to 50 ± 10 N·m (37 ± 7 ft-lbs).
- Reconnect the electrical plug — ensure it clicks into place securely.
- Reconnect battery and start the engine.
- Clear fault codes using a diagnostic scanner and verify no new codes appear.
Pro Tips for Long Sensor Life
✅ Avoid touching the ceramic sensing tip with bare hands (oil contamination causes premature failure)
✅ Do not drop or impact the sensor — the ceramic element is fragile
✅ Route the cable away from hot exhaust pipes and moving parts
✅ Replace both inlet and outlet NOx sensors at the same time for balanced SCR performance
Frequently Asked Questions (FAQ)
Q: Is this the inlet or outlet NOx sensor?
A: The 4326872 / A045S169 is the outlet (downstream) NOx sensor, located after the SCR catalyst. If you need the inlet sensor, check our listing for part number 2894940RX or contact us for assistance.
Q: Will this sensor work on my 2016 Cummins ISX15?
A: Yes — the WJIECO 4326872 is compatible with Cummins ISX15 engines from 2011 through 2018. Always verify your original OE number matches 4326872, 4326872RX, or A045S169 before ordering.
Q: Do I need to program or calibrate the sensor after installation?
A: No. The WJIECO 4326872 NOx sensor is pre-calibrated and ready to use. Simply install it, clear existing fault codes, and your ECU will handle the rest. No dealer-level programming required.
Q: How long does a NOx sensor typically last?
A: OEM NOx sensors are rated for approximately 100,000–150,000 miles under normal operating conditions. WJIECO sensors match this lifespan. Factors that shorten sensor life include excessive oil consumption, coolant leaks into exhaust, and poor-quality DEF fluid.
Q: What’s the difference between 4326872 and 4326872RX?
A: 4326872 is the new OEM part number, while 4326872RX is the remanufactured (rebuilt) version from Cummins. Both are functionally identical. WJIECO’s aftermarket replacement works with both cross-references.
Q: Can a bad NOx sensor cause derate?
A: Absolutely. A faulty outlet NOx sensor is one of the most common causes of engine derate on Cummins ISX engines. The ECU will trigger a 5-hour countdown derate if it detects persistent NOx sensor faults, eventually limiting vehicle speed to 5 mph. Replacing the sensor with a WJIECO 4326872 unit resolves this issue.
Get Your WJIECO 4326872 NOx Sensor Today
Don’t let a failing NOx sensor leave you stranded with a derated engine or failed emissions test. The WJIECO 4326872 / 4326872RX / A045S169 nitrogen oxide sensor delivers OEM-quality performance at aftermarket pricing — trusted by fleets, repair shops, and owner-operators across North America and Europe.
📦 In Stock & Ready to Ship — Most orders dispatched within 24 hours
🛡️ 12-Month Warranty — Full replacement coverage
🔧 Technical Support — 24-hour response for fitment and troubleshooting
💸 Wholesale Pricing — Volume discounts for fleets and repair shops
