4163699C91 | Genuine OEM International/Navistar DEF QLS Header 15.5–23G

The 4163699C91 Genuine OEM International/Navistar DEF QLS Header is a diesel exhaust fluid tank header assembly designed for compatible International truck DEF systems. It integrates the required DEF sensing and fluid management components at the tank and is designed for compatible 15.5–23 gallon DEF tank applications.

PRODUCT INFORMATION

Part Number: 4163699C91
Brand: International® / Navistar®
Condition: New
Component: DEF QLS Header
Fuel Type: Diesel
DEF Tank Capacity: 15.5–23 Gallons
System: Diesel Exhaust Fluid (DEF) / SCR
Sensor Technology: QLS (Quality Level Sensor)

APPLICATIONS

Compatible with selected International/Navistar diesel truck applications using compatible 15.5–23 gallon DEF tanks. Exact fitment depends on the truck model, model year, DEF tank configuration, electrical connections, and emissions system.

FUNCTION

The DEF QLS Header is installed in the DEF tank and supports monitoring of DEF level, quality, and related tank operating parameters. It works as part of the vehicle's DEF/SCR aftertreatment system.

A worn, damaged, or failing DEF QLS Header may cause symptoms such as:

• DEF level readings that are inaccurate
• DEF quality monitoring faults
• DEF system warning messages
• SCR or aftertreatment fault codes
• Incorrect DEF tank sensor readings
• Check engine or emissions system warnings

WHY REPLACE A DEF QLS HEADER?

A damaged or malfunctioning DEF QLS Header can affect DEF level and quality monitoring and may contribute to aftertreatment system faults. Replacing the header with the correct OEM component can help restore proper DEF tank sensing and system operation.

FITMENT INFORMATION

Description contains the focus keyword 2–4 times per 300 words.

Please verify Part Number, VIN, truck model, model year, DEF tank capacity, tank configuration, electrical connections, and emissions system before ordering.

If you are unsure whether this part is correct for your vehicle, please contact us with your VIN and original part number. We are happy to help verify compatibility before purchase.

GENUINE INTERNATIONAL® / NAVISTAR® PART

Part Number: 4163699C91