Volvo 22827992 and 22827993 NOx Sensor Guide

Overview

Volvo NOx sensors 22827992 (5WK97373) and 22827993 (5WK97371) monitor diesel emissions and feed raw NOx concentration data to the engine control unit (ECU). The ECU uses that data to adjust the urea injection in the SCR system. When the sensor reads correctly, the engine stays within its emissions limits. When it drifts, you get fault codes, a lit warning lamp, and usually a power derate.

What each part number covers

22827992 (5WK97373) and 22827993 (5WK97371) are the two sensor positions used across the Volvo D13 and related heavy-duty platforms. They are not interchangeable by location, so match the number to the position the fault code points to before ordering. The connector, thread, and cable length differ between positions, and forcing the wrong one causes harness strain or a poor seal.

Why measurement accuracy matters

The sensor has to read NOx concentration fast and hold that accuracy as exhaust temperature swings. Getting this right is what keeps the SCR system dosing the correct amount of urea. Undershoot and you fail emissions; overshoot and you dump urea you did not need, which clogs the injector and the catalyst over time. The tolerance is tighter than most people expect, which is why a worn or slow sensor throws a code long before the truck feels different to drive.

Fit and reliability

These sensors are built to Volvo’s dimensions, so they seat and connect without modification. Proper seating matters more than it sounds: a sensor that sits proud of the boss leaks exhaust and reads wrong. Torque the mounting to spec, seat the connector fully, and the unit performs like the original.

Cross-reference and sourcing

If you have the VIN or the OE number from the failed unit, send it over and we will confirm the exact position and cable variant. SHR stocks both 22827992 and 22827993 with OE-matching calibration, so the replacement drops in without recalibration headaches.