FITMENT:
Compatible with Volvo and Mack heavy-duty trucks equipped with SCR (AdBlue/DEF) emission systems, including:

• Volvo VNL / VNR / FM / FH series (D11, D13, D16 engines)
• Mack CXU / CHU / GU / Pinnacle series
• Mack MP7 / MP8 engines
• Select Cummins-powered OEM integrations (depending on SCR layout)

OEM / Cross reference numbers:

• 22303391
• 21567763
• 21069361
• 21636088 / 21479637 / 21346963 (related interchange family)
• 5WK9 7366 / 5WK97366

This is a post-SCR (outlet) NOx sensor used in Volvo/Mack emissions systems for downstream monitoring of catalytic efficiency.

FUNCTION:

• Measures nitrogen oxide (NOx) levels after SCR catalyst
• Sends data to ECM for AdBlue dosing correction
• Monitors SCR catalyst efficiency and emissions performance
• Helps prevent derate and emission system faults

INSTALLATION POSITION:

• Outlet / post-catalyst NOx sensor
• Mounted after SCR catalyst on exhaust system (tailpipe side of aftertreatment)

FAQ:

Q1: Is this inlet or outlet sensor?
A1: This part number family (22303391 / 21567763 / 21069361) is commonly used as the outlet (post-SCR) NOx sensor on Volvo/Mack systems.

Q2: What trucks does it fit?
A2: Volvo FH/FM/D13/D16 engines and Mack MP7/MP8 platforms.

Q3: Are all part numbers interchangeable?
A3: They belong to the same sensor family, but exact compatibility depends on harness length, mounting style, and ECU calibration.

Q4: What are failure symptoms?
A4: SCR warning light, engine derate, incorrect NOx readings, DEF system faults, or reduced engine power.

Q5: Does replacement require programming?
A5: Some Volvo/Mack trucks require SCR reset or ECU adaptation after installation.