22303391 | Genuine Volvo / Mack Outlet NOx Sensor

The Genuine OEM Volvo / Mack NOx Sensor, part number 22303391, monitors nitrogen oxide (NOx) levels in the exhaust aftertreatment system of compatible heavy-duty diesel trucks. This outlet sensor provides emissions data used by the Selective Catalytic Reduction (SCR) system to monitor exhaust treatment performance.

PRODUCT INFORMATION

• Part Number: 22303391

• Brand: Volvo / Mack

• Part Name: Nitrogen Oxide (NOx) Sensor

• Sensor Position: Outlet / Downstream (post-SCR)

• Engine Applications: Volvo D11, D13; Mack MP7, MP8

• System: Exhaust Aftertreatment / SCR

• Condition: Confirm the actual condition before publishing

APPLICATIONS

This sensor is listed for selected Volvo D11 and D13 and Mack MP7 and MP8 engine applications. Some catalog listings show applications in 2010–2018 trucks, but exact compatibility depends on the vehicle, emissions configuration, and sensor position.

FUNCTION

The outlet NOx sensor measures nitrogen oxide levels in the exhaust after it passes through the SCR catalyst. Its readings help the engine and emissions control system monitor NOx reduction performance.

COMMON SIGNS OF SENSOR FAILURE

• Check engine or emissions system warning lights

• NOx sensor or SCR-related fault codes

• Implausible or inconsistent NOx readings

• Sensor circuit, heater, or communication faults

• Possible engine derate caused by an aftertreatment fault

These symptoms can have other causes and should be confirmed through diagnostics.

WHY REPLACE

A defective NOx sensor can provide inaccurate exhaust readings and interfere with emissions system monitoring. Replacing a confirmed faulty sensor with the correct part helps restore reliable NOx measurement and SCR system operation.

FITMENT INFORMATION

Part number 22303391 is associated with selected Volvo D11/D13 and Mack MP7/MP8 applications. Verify the original part number, outlet sensor position, connector, engine configuration, and vehicle identification before ordering. Do not confuse this outlet sensor with an inlet NOx sensor.

GENUINE VOLVO / MACK PART

This listing identifies OEM part number 22303391, a Genuine Volvo / Mack Outlet NOx Sensor for compatible heavy-duty diesel truck exhaust aftertreatment systems.