WJIECO 4326872 NOx Sensor Durable Cross references 4326872RX, A045S169, 5WK96749A, 5WK96749B. OEM-grade downstream NOx Sensor for 2013–2018 Dodge Ram 2500 3500 4500 5500 6.7L Cummins Diesel. SCR monitoring, plug & play install.

4326872 NOx Sensor Overview

The 4326872 NOx Sensor manufactured by WJIECO is a critical feedback component of the SCR exhaust emission system on US-spec Dodge Ram heavy-duty trucks with the 6.7L Cummins diesel engine. This unit is installed downstream, after the SCR catalyst. While the upstream NOx Sensor tells the ECU how much NOx is entering the catalyst, this downstream NOx Sensor checks how much NOx remains after the SCR reaction is complete.

The engine control module relies on this downstream reading to confirm the SCR catalyst and DEF injection system are working correctly. A faulty NOx Sensor in this position will trigger check engine lights, set SCR efficiency fault codes, trigger power derate modes, and prevent the truck from passing state emissions testing. Many diesel technicians see this sensor fail from heat fatigue, soot buildup, or internal chip drift, creating intermittent codes that only show up under sustained highway load. This sensor cross-references interchange numbers: 4326872, 4326872RX, A045S169, 5WK96749A, 5WK96749B for fast lookup for DIY owners, repair shops and commercial fleets.

H2: OEM-Grade Construction & Strict Factory Testing

Our 4326872 NOx Sensor adopts a high-stability ceramic sensing core, robust heat-resistant metal housing, and fully sealed cable assembly engineered to survive extreme exhaust heat, constant engine vibration, rapid thermal cycling, and road contaminants like salt, mud and moisture. Low-cost generic NOx Sensors often skip strict aging calibration, leading to signal drift after only a few thousand miles, especially when exposed to winter road salt common across North America.

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WJIECO 4326873 NOx Sensor Durable Cross references 5WK96742B, 2872948. OEM-grade upstream NOx Sensor for 2013–2018 Dodge Ram 2500 3500 4500 5500 6.7L Cummins Diesel. SCR system control, plug & play install.

Every finished NOx Sensor undergoes complete factory calibration, signal accuracy validation, long-duration aging testing, waterproof sealing inspection and connector pin continuity checks before packaging. This multi-step quality control ensures consistent NOx readings, reliable ECU communication, and extended service life in the punishing aftertreatment environment of Cummins diesel pickups and chassis cabs.

H2: Vehicle Fitment (US Market Fitment List)

Standard US fitment format, matches Cummins / Ram OEM catalog:

• Dodge Ram 2500 6.7L Cummins Diesel (MY 2013–2018, US Spec)
• Dodge Ram 3500 6.7L Cummins Diesel (MY 2013–2018, US Spec)
• Dodge Ram 4500 6.7L Cummins Diesel (MY 2013–2018, US Spec)
• Dodge Ram 5500 6.7L Cummins Diesel (MY 2013–2018, US Spec)

Important note: This is the DOWNSTREAM NOx Sensor. Do not confuse it with the upstream NOx Sensor (4326873). Verify your VIN, sensor mounting position after the SCR canister and original OEM part number before ordering. Swapping upstream and downstream NOx Sensors will cause persistent SCR monitoring failures.

Interchange OE Numbers: 4326872, 4326872RX, A045S169, 5WK96749A, 5WK96749B

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H2: Core Benefits of 4326872 NOx Sensor

Installing the WJIECO 4326872 NOx Sensor to replace your failed downstream unit restores closed-loop feedback for the SCR system. Accurate post-catalyst NOx measurements let the ECU validate SCR conversion efficiency, clear efficiency-related DTCs, remove reduced-power derate restrictions, and help the truck complete emissions readiness monitors for inspection. For fleet operators, fixing a bad downstream NOx Sensor quickly avoids unexpected roadside shutdowns and lost work hours.

Durable construction minimizes early failures and intermittent fault codes that plague cheap alternatives. This aftermarket NOx Sensor delivers OEM-matching performance at a fraction of the dealership replacement price, a great fit for commercial fleets, backyard Ram enthusiasts, and professional diesel repair garages.

H2: Plug-and-Play Installation, No Dealer Programming Required

This 4326872 NOx Sensor is a true direct-fit replacement for the factory downstream sensor on Ram 6.7 Cummins models. Thread size, mounting flange, connector shape, and internal wiring pinout all match OEM specifications perfectly. Remove the old sensor, thread in the new unit, torque it to proper specs, and reconnect the factory wiring harness. There is no wire cutting, harness modification, or ECU reflash programming required. After installation, clear all associated diagnostic trouble codes with a suitable heavy-duty scan tool and perform an extended test drive. A full drive cycle is recommended so the ECM can run its SCR efficiency self-test and reset readiness status.

Every WJIECO 4326872 NOx Sensor is fully bench-tested before shipment. If you need a dependable downstream NOx Sensor compatible with 4326872, 4326872RX, A045S169, 5WK96749A, 5WK96749B for your 2013–2018 Ram 6.7 Cummins, this WJIECO NOx Sensor will get your emissions system back into working order.

Product Tags

4326872, 4326872RX, A045S169, 5WK96749A, 5WK96749B, NOx Sensor, Nitrogen Oxide Sensor, Ram 6.7 Cummins NOx sensor, Dodge Ram downstream NOx sensor, diesel SCR NOx sensor, WJIECO exhaust sensor