Application & Compatibility

The MCT CM4939 is an exhaust NOx sensor marketed as a compatible replacement for Cummins part number 2894939. Listed by heavy-duty parts distributors in the exhaust/NOx sensor category, it is identified specifically with the 2894939 OEM reference for straightforward service and parts selection. This targeted cross-reference helps technicians match the correct sensor to vehicles originally equipped with the Cummins 2894939, minimizing guesswork during repairs and reducing time to return a unit to service.

Function in Aftertreatment

Installed in the exhaust aftertreatment stream, the sensor monitors nitrogen oxides (NOx) and provides measurement data to the engine or emissions control system. Accurate NOx feedback supports proper operation of the vehicle’s emissions strategy, including control of the SCR system, so the aftertreatment can function as intended. By restoring the NOx measurement pathway in applications that specify 2894939, the CM4939 helps maintain emissions performance when the overall system is operating correctly.

Service & Selection Notes

Available product listings emphasize application fit as a replacement for Cummins 2894939 and do not detail dimensional, electrical, or connector specifications. Verify part selection by confirming the OEM reference and vehicle application prior to installation. Choosing a component that is cross-referenced to the original part number aids service accuracy and supports reliable emissions monitoring in the field.